Explicit feedback format within single user, multiple user, multiple access, and/or MIMO wireless communications

ABSTRACT

Explicit feedback format within single user, multiple user, multiple access, and/or MIMO wireless communications. A beamformer provides a first communication to a beamformee, and based thereon, the beamformee may ascertain certain characteristics associated with the type and format of feedback to be provided to the beamformee via a second communication from the beamformee to the beamformer. For example, the first communication may include indication of a current operational mode, such as whether it is in accordance with single-user multiple input multiple output (SU-MIMO) or multi-user multiple-input-multiple-output (MU-MIMO). Also, the first communication may indicate a requested steering matrix&#39;s rank to be employed in accordance with subsequent beamforming by the beamformer. Also, additional information such as that pertaining to per-tone SNR values for each respective space-time stream, per-tone or per-sub-band eigen-values, the particular channel width being employed (e.g., 20, 40, 80, or 160 MHz), etc. may be included within the second communication.

CROSS REFERENCE TO RELATED PATENTS/PATENT APPLICATIONS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. §120 as a continuation of U.S. Utility application Ser. No.13/955,070, entitled “Explicit feedback format within single user,multiple user, multiple access, and/or MIMO wireless communications”,filed Jul. 31, 2013, pending, and scheduled subsequently to be issued asU.S. Pat. No. 9,356,664 on May 31, 2016 (as indicated in an ISSUENOTIFICATION mailed from the USPTO on May 11, 2016), which is acontinuation of U.S. Utility application Ser. No. 13/196,721, entitled“Explicit feedback format within single user, multiple user, multipleaccess, and/or MIMO wireless communications,” filed Aug. 2, 2011, nowissued as U.S. Pat. No. 8,520,576 on Aug. 27, 2013, which claimspriority pursuant to 35 U.S.C. §119(e) to U.S. Provisional ApplicationNo. 61/370,785, entitled “Explicit feedback format within single user,multiple user, multiple access, and/or MIMO wireless communications,”filed Aug. 4, 2010, and U.S. Provisional Application No. 61/390,569,entitled “Explicit feedback format within single user, multiple user,multiple access, and/or MIMO wireless communications,” filed Oct. 6,2010, all of which are hereby incorporated herein by reference in theirentirety and made part of the present U.S. Utility Patent Applicationfor all purposes.

INCORPORATION BY REFERENCE

The following IEEE standards are hereby incorporated herein by referencein their entirety and are made part of the present U.S. Utility PatentApplication for all purposes:

1. IEEE Std 802.11™—2007, “IEEE Standard for Informationtechnology—Telecommunications and information exchange betweensystems—Local and metropolitan area networks—Specific requirements; Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)Specifications,” IEEE Computer Society, IEEE Std 802.11™—2007, (Revisionof IEEE Std 802.11—1999), 1233 pages.

2. IEEE Std 802.11n™—2009, “IEEE Standard for Informationtechnology—Telecommunications and information exchange betweensystems—Local and metropolitan area networks—Specific requirements; Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)Specifications; Amendment 5: Enhancements for Higher Throughput,” IEEEComputer Society, IEEE Std 802.11n™—2009, (Amendment to IEEE Std802.11™—2007 as amended by IEEE Std 802.11k™—2008, IEEE Std802.11r™—2008, IEEE Std 802.11y™—2008, and IEEE Std 802.11r™—2009), 536pages.

3. IEEE P802.11ac™/D1.0, May 2011, “Draft STANDARD for InformationTechnology—Telecommunications and information exchange betweensystems—Local and metropolitan area networks—Specific requirements, Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)specifications, Amendment 5: Enhancements for Very High Throughput forOperation in Bands below 6 GHz,” Prepared by the 802.11 Working Group ofthe 802 Committee, 263 total pages (pp. i-xxi, 1-242).

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The invention relates generally to communication systems; and, moreparticularly, it relates to formatting in accordance with providingexplicit feedback within single user, multiple user, multiple access,and/or MIMO wireless communications.

2. Description of Related Art

Communication systems are known to support wireless and wire linedcommunications between wireless and/or wire lined communication devices.Such communication systems range from national and/or internationalcellular telephone systems to the Internet to point-to-point in-homewireless networks. Each type of communication system is constructed, andhence operates, in accordance with one or more communication standards.For instance, wireless communication systems may operate in accordancewith one or more standards including, but not limited to, IEEE 802.11x,Bluetooth, advanced mobile phone services (AMPS), digital AMPS, globalsystem for mobile communications (GSM), code division multiple access(CDMA), local multi-point distribution systems (LMDS),multi-channel-multi-point distribution systems (MMDS), and/or variationsthereof.

Depending on the type of wireless communication system, a wirelesscommunication device, such as a cellular telephone, two-way radio,personal digital assistant (PDA), personal computer (PC), laptopcomputer, home entertainment equipment, et cetera communicates directlyor indirectly with other wireless communication devices. For directcommunications (also known as point-to-point communications), theparticipating wireless communication devices tune their receivers andtransmitters to the same channel or channels (e.g., one of the pluralityof radio frequency (RF) carriers of the wireless communication system)and communicate over that channel(s). For indirect wirelesscommunications, each wireless communication device communicates directlywith an associated base station (e.g., for cellular services) and/or anassociated access point (e.g., for an in-home or in-building wirelessnetwork) via an assigned channel. To complete a communication connectionbetween the wireless communication devices, the associated base stationsand/or associated access points communicate with each other directly,via a system controller, via the public switch telephone network, viathe Internet, and/or via some other wide area network.

For each wireless communication device to participate in wirelesscommunications, it includes a built-in radio transceiver (i.e., receiverand transmitter) or is coupled to an associated radio transceiver (e.g.,a station for in-home and/or in-building wireless communicationnetworks, RF modem, etc.). As is known, the receiver is coupled to theantenna and includes a low noise amplifier, one or more intermediatefrequency stages, a filtering stage, and a data recovery stage. The lownoise amplifier receives inbound RF signals via the antenna andamplifies them. The one or more intermediate frequency stages mix theamplified RF signals with one or more local oscillations to convert theamplified RF signal into baseband signals or intermediate frequency (IF)signals. The filtering stage filters the baseband signals or the IFsignals to attenuate unwanted out of band signals to produce filteredsignals. The data recovery stage recovers raw data from the filteredsignals in accordance with the particular wireless communicationstandard.

As is also known, the transmitter includes a data modulation stage, oneor more intermediate frequency stages, and a power amplifier. The datamodulation stage converts raw data into baseband signals in accordancewith a particular wireless communication standard. The one or moreintermediate frequency stages mix the baseband signals with one or morelocal oscillations to produce RF signals. The power amplifier amplifiesthe RF signals prior to transmission via an antenna.

Typically, the transmitter will include one antenna for transmitting theRF signals, which are received by a single antenna, or multiple antennae(alternatively, antennas), of a receiver. When the receiver includes twoor more antennae, the receiver will select one of them to receive theincoming RF signals. In this instance, the wireless communicationbetween the transmitter and receiver is a single-output-single-input(SISO) communication, even if the receiver includes multiple antennaethat are used as diversity antennae (i.e., selecting one of them toreceive the incoming RF signals). For SISO wireless communications, atransceiver includes one transmitter and one receiver. Currently, mostwireless local area networks (WLAN) that are IEEE 802.11, 802.11a,802.11b, or 802.11g employ SISO wireless communications.

Other types of wireless communications includesingle-input-multiple-output (SIMO), multiple-input-single-output(MISO), and multiple-input-multiple-output (MIMO). In a SIMO wirelesscommunication, a single transmitter processes data into radio frequencysignals that are transmitted to a receiver. The receiver includes two ormore antennae and two or more receiver paths. Each of the antennaereceives the RF signals and provides them to a corresponding receiverpath (e.g., LNA, down conversion module, filters, and ADCs). Each of thereceiver paths processes the received RF signals to produce digitalsignals, which are combined and then processed to recapture thetransmitted data.

For a multiple-input-single-output (MISO) wireless communication, thetransmitter includes two or more transmission paths (e.g., digital toanalog converter, filters, up-conversion module, and a power amplifier)that each converts a corresponding portion of baseband signals into RFsignals, which are transmitted via corresponding antennae to a receiver.The receiver includes a single receiver path that receives the multipleRF signals from the transmitter. In this instance, the receiver usesbeam forming to combine the multiple RF signals into one signal forprocessing.

For a multiple-input-multiple-output (MIMO) wireless communication, thetransmitter and receiver each include multiple paths. In such acommunication, the transmitter parallel processes data using a spatialand time encoding function to produce two or more streams of data. Thetransmitter includes multiple transmission paths to convert each streamof data into multiple RF signals. The receiver receives the multiple RFsignals via multiple receiver paths that recapture the streams of datautilizing a spatial and time decoding function. The recaptured streamsof data are combined and subsequently processed to recover the originaldata.

With the various types of wireless communications (e.g., SISO, MISO,SIMO, and MIMO), it would be desirable to use one or more types ofwireless communications to enhance data throughput within a WLAN. Forexample, high data rates can be achieved with MIMO communications incomparison to SISO communications. However, most WLAN include legacywireless communication devices (i.e., devices that are compliant with anolder version of a wireless communication standard). As such, atransmitter capable of MIMO wireless communications should also bebackward compatible with legacy devices to function in a majority ofexisting WLANs.

Therefore, a need exists for a WLAN device that is capable of high datathroughput and is backward compatible with legacy devices.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a diagram illustrating an embodiment of a wirelesscommunication system.

FIG. 2 is a diagram illustrating an embodiment of a wirelesscommunication device.

FIG. 3 is a diagram illustrating an embodiment of a radio frequency (RF)transmitter.

FIG. 4 is a diagram illustrating an embodiment of an RF receiver.

FIG. 5 is a diagram illustrating an embodiment of a method for basebandprocessing of data.

FIG. 6 is a diagram illustrating an embodiment of a method that furtherdefines Step 120 of FIG. 5.

FIGS. 7-9 are diagrams illustrating various embodiments for encoding thescrambled data.

FIGS. 10A and 10B are diagrams illustrating embodiments of a radiotransmitter.

FIGS. 11A and 11B are diagrams illustrating embodiments of a radioreceiver.

FIG. 12 is a diagram illustrating an embodiment of an access point (AP)and multiple wireless local area network (WLAN) devices operatingaccording to one or more various aspects and/or embodiments of theinvention.

FIG. 13 is a diagram illustrating an embodiment of a wirelesscommunication device, and clusters, as may be employed for supportingcommunications with at least one additional wireless communicationdevice.

FIG. 14, FIG. 15, FIG. 16, and FIG. 17 are diagrams illustrating variousembodiments of simulation results showing the effects of feedback rankand accuracy.

FIG. 18 is a diagram illustrating an embodiment of an angle resolutiontable.

FIG. 19 is a diagram illustrating an embodiment of a tables respectivelyshowing resulting fed back tones with different baseline tone grouping,and particularly, showing tone grouping 2 (with added tone grouping of 1in zones 1 and 2) and tone grouping 4 (with added tone grouping of 1 inzone 1).

FIG. 20 is a diagram illustrating an embodiment of a very highthroughput (VHT) long multiple input multiple output (MIMO) controlfield and feedback field formats for multi-user (MU) and single-user(SU), respectively.

FIG. 21 is a diagram illustrating an embodiment of a codebookinformation table with 2 bits in the feedback report.

FIG. 22 is a diagram illustrating an embodiment of a simulation for SUwith 8 transmit antennae.

FIG. 23 is a diagram illustrating an embodiment of a VHT MIMO controlfield.

FIG. 24 is a diagram illustrating an embodiment of tone mapping withgrouping.

FIG. 25 is a diagram illustrating an embodiment of a simulation resultscorresponding to a communication system in which a transmitting wirelesscommunication device has 4 antennae and each of 4 receiving wirelesscommunication devices has a respective 1 antenna.

FIG. 26 is a diagram illustrating an embodiment of per-tone signal tonoise ratio (SNR) field in a MU-exclusive beamforming report.

FIG. 27A, FIG. 27B, and FIG. 27C illustrate various embodiments ofmethods for operating a communication device.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a diagram illustrating an embodiment of a wirelesscommunication system 10 that includes a plurality of base stationsand/or access points 12-16, a plurality of wireless communicationdevices 18-32 and a network hardware component 34. The wirelesscommunication devices 18-32 may be laptop host computers 18 and 26,personal digital assistant hosts 20 and 30, personal computer hosts 24and 32 and/or cellular telephone hosts 22 and 28. The details of anembodiment of such wireless communication devices is described ingreater detail with reference to FIG. 2.

The base stations (BSs) or access points (APs) 12-16 are operablycoupled to the network hardware 34 via local area network connections36, 38 and 40. The network hardware 34, which may be a router, switch,bridge, modem, system controller, et cetera provides a wide area networkconnection 42 for the communication system 10. Each of the base stationsor access points 12-16 has an associated antenna or antenna array tocommunicate with the wireless communication devices in its area.Typically, the wireless communication devices register with a particularbase station or access point 12-14 to receive services from thecommunication system 10. For direct connections (i.e., point-to-pointcommunications), wireless communication devices communicate directly viaan allocated channel.

Typically, base stations are used for cellular telephone systems (e.g.,advanced mobile phone services (AMPS), digital AMPS, global system formobile communications (GSM), code division multiple access (CDMA), localmulti-point distribution systems (LMDS), multi-channel-multi-pointdistribution systems (MMDS), Enhanced Data rates for GSM Evolution(EDGE), General Packet Radio Service (GPRS), high-speed downlink packetaccess (HSDPA), high-speed uplink packet access (HSDPA and/or variationsthereof) and like-type systems, while access points are used for in-homeor in-building wireless networks (e.g., IEEE 802.11, Bluetooth, ZigBee,any other type of radio frequency based network protocol and/orvariations thereof). Regardless of the particular type of communicationsystem, each wireless communication device includes a built-in radioand/or is coupled to a radio. Such wireless communication devices mayoperate in accordance with the various aspects of the invention aspresented herein to enhance performance, reduce costs, reduce size,and/or enhance broadband applications.

FIG. 2 is a diagram illustrating an embodiment of a wirelesscommunication device that includes the host device 18-32 and anassociated radio 60. For cellular telephone hosts, the radio 60 is abuilt-in component. For personal digital assistants hosts, laptop hosts,and/or personal computer hosts, the radio 60 may be built-in or anexternally coupled component. For access points or base stations, thecomponents are typically housed in a single structure.

As illustrated, the host device 18-32 includes a processing module 50,memory 52, radio interface 54, input interface 58 and output interface56. The processing module 50 and memory 52 execute the correspondinginstructions that are typically done by the host device. For example,for a cellular telephone host device, the processing module 50 performsthe corresponding communication functions in accordance with aparticular cellular telephone standard.

The radio interface 54 allows data to be received from and sent to theradio 60. For data received from the radio 60 (e.g., inbound data), theradio interface 54 provides the data to the processing module 50 forfurther processing and/or routing to the output interface 56. The outputinterface 56 provides connectivity to an output display device such as adisplay, monitor, speakers, et cetera such that the received data may bedisplayed. The radio interface 54 also provides data from the processingmodule 50 to the radio 60. The processing module 50 may receive theoutbound data from an input device such as a keyboard, keypad,microphone, et cetera via the input interface 58 or generate the dataitself. For data received via the input interface 58, the processingmodule 50 may perform a corresponding host function on the data and/orroute it to the radio 60 via the radio interface 54.

Radio 60 includes a host interface 62, a baseband processing module 64,memory 66, a plurality of radio frequency (RF) transmitters 68-72, atransmit/receive (T/R) module 74, a plurality of antennae 82-86, aplurality of RF receivers 76-80, and a local oscillation module 100. Thebaseband processing module 64, in combination with operationalinstructions stored in memory 66, execute digital receiver functions anddigital transmitter functions, respectively. The digital receiverfunctions, as will be described in greater detail with reference to FIG.11B, include, but are not limited to, digital intermediate frequency tobaseband conversion, demodulation, constellation demapping, decoding,de-interleaving, fast Fourier transform, cyclic prefix removal, spaceand time decoding, and/or descrambling. The digital transmitterfunctions, as will be described in greater detail with reference tolater Figures, include, but are not limited to, scrambling, encoding,interleaving, constellation mapping, modulation, inverse fast Fouriertransform, cyclic prefix addition, space and time encoding, and/ordigital baseband to IF conversion. The baseband processing modules 64may be implemented using one or more processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on operationalinstructions. The memory 66 may be a single memory device or a pluralityof memory devices. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, and/or any device that storesdigital information. Note that when the processing module 64 implementsone or more of its functions via a state machine, analog circuitry,digital circuitry, and/or logic circuitry, the memory storing thecorresponding operational instructions is embedded with the circuitrycomprising the state machine, analog circuitry, digital circuitry,and/or logic circuitry.

In operation, the radio 60 receives outbound data 88 from the hostdevice via the host interface 62. The baseband processing module 64receives the outbound data 88 and, based on a mode selection signal 102,produces one or more outbound symbol streams 90. The mode selectionsignal 102 will indicate a particular mode as are illustrated in themode selection tables, which appear at the end of the detaileddiscussion. For example, the mode selection signal 102, with referenceto table 1 may indicate a frequency band of 2.4 GHz or 5 GHz, a channelbandwidth of 20 or 22 MHz (e.g., channels of 20 or 22 MHz width) and amaximum bit rate of 54 megabits-per-second. In other embodiments, thechannel bandwidth may extend up to 1.28 GHz or wider with supportedmaximum bit rates extending to 1 gigabit-per-second or greater. In thisgeneral category, the mode selection signal will further indicate aparticular rate ranging from 1 megabit-per-second to 54megabits-per-second. In addition, the mode selection signal willindicate a particular type of modulation, which includes, but is notlimited to, Barker Code Modulation, BPSK, QPSK, CCK, 16 QAM and/or 64QAM. As is further illustrated in table 1, a code rate is supplied aswell as number of coded bits per subcarrier (NBPSC), coded bits per OFDMsymbol (NCBPS), data bits per OFDM symbol (NDBPS).

The mode selection signal may also indicate a particular channelizationfor the corresponding mode which for the information in table 1 isillustrated in table 2. As shown, table 2 includes a channel number andcorresponding center frequency. The mode select signal may furtherindicate a power spectral density mask value which for table 1 isillustrated in table 3. The mode select signal may alternativelyindicate rates within table 4 that has a 5 GHz frequency band, 20 MHzchannel bandwidth and a maximum bit rate of 54 megabits-per-second. Ifthis is the particular mode select, the channelization is illustrated intable 5. As a further alternative, the mode select signal 102 mayindicate a 2.4 GHz frequency band, 20 MHz channels and a maximum bitrate of 192 megabits-per-second as illustrated in table 6. In table 6, anumber of antennae may be utilized to achieve the higher bit rates. Inthis instance, the mode select would further indicate the number ofantennae to be utilized. Table 7 illustrates the channelization for theset-up of table 6. Table 8 illustrates yet another mode option where thefrequency band is 2.4 GHz, the channel bandwidth is 20 MHz and themaximum bit rate is 192 megabits-per-second. The corresponding table 8includes various bit rates ranging from 12 megabits-per-second to 216megabits-per-second utilizing 2-4 antennae and a spatial time encodingrate as indicated. Table 9 illustrates the channelization for table 8.The mode select signal 102 may further indicate a particular operatingmode as illustrated in table 10, which corresponds to a 5 GHz frequencyband having 40 MHz frequency band having 40 MHz channels and a maximumbit rate of 486 megabits-per-second. As shown in table 10, the bit ratemay range from 13.5 megabits-per-second to 486 megabits-per-secondutilizing 1-4 antennae and a corresponding spatial time code rate. Table10 further illustrates a particular modulation scheme code rate andNBPSC values. Table 11 provides the power spectral density mask fortable 10 and table 12 provides the channelization for table 10.

It is of course noted that other types of channels, having differentbandwidths, may be employed in other embodiments without departing fromthe scope and spirit of the invention. For example, various otherchannels such as those having 80 MHz, 120 MHz, and/or 160 MHz ofbandwidth may alternatively be employed such as in accordance with IEEETask Group ac (TGac VHTL6).

The baseband processing module 64, based on the mode selection signal102 produces the one or more outbound symbol streams 90, as will befurther described with reference to FIGS. 5-9 from the output data 88.For example, if the mode selection signal 102 indicates that a singletransmit antenna is being utilized for the particular mode that has beenselected, the baseband processing module 64 will produce a singleoutbound symbol stream 90. Alternatively, if the mode select signalindicates 2, 3 or 4 antennae, the baseband processing module 64 willproduce 2, 3 or 4 outbound symbol streams 90 corresponding to the numberof antennae from the output data 88.

Depending on the number of outbound streams 90 produced by the basebandmodule 64, a corresponding number of the RF transmitters 68-72 will beenabled to convert the outbound symbol streams 90 into outbound RFsignals 92. The implementation of the RF transmitters 68-72 will befurther described with reference to FIG. 3. The transmit/receive module74 receives the outbound RF signals 92 and provides each outbound RFsignal to a corresponding antenna 82-86.

When the radio 60 is in the receive mode, the transmit/receive module 74receives one or more inbound RF signals via the antennae 82-86. The T/Rmodule 74 provides the inbound RF signals 94 to one or more RF receivers76-80. The RF receiver 76-80, which will be described in greater detailwith reference to FIG. 4, converts the inbound RF signals 94 into acorresponding number of inbound symbol streams 96. The number of inboundsymbol streams 96 will correspond to the particular mode in which thedata was received (recall that the mode may be any one of the modesillustrated in tables 1-12). The baseband processing module 64 receivesthe inbound symbol streams 90 and converts them into inbound data 98,which is provided to the host device 18-32 via the host interface 62.

In one embodiment of radio 60 it includes a transmitter and a receiver.The transmitter may include a MAC module, a PLCP module, and a PMDmodule. The Medium Access Control (MAC) module, which may be implementedwith the processing module 64, is operably coupled to convert a MACService Data Unit (MSDU) into a MAC Protocol Data Unit (MPDU) inaccordance with a WLAN protocol. The Physical Layer ConvergenceProcedure (PLCP) Module, which may be implemented in the processingmodule 64, is operably coupled to convert the MPDU into a PLCP ProtocolData Unit (PPDU) in accordance with the WLAN protocol. The PhysicalMedium Dependent (PMD) module is operably coupled to convert the PPDUinto a plurality of radio frequency (RF) signals in accordance with oneof a plurality of operating modes of the WLAN protocol, wherein theplurality of operating modes includes multiple input and multiple outputcombinations.

An embodiment of the Physical Medium Dependent (PMD) module, which willbe described in greater detail with reference to FIGS. 10A and 10B,includes an error protection module, a demultiplexing module, and aplurality of direction conversion modules. The error protection module,which may be implemented in the processing module 64, is operablycoupled to restructure a PPDU (PLCP (Physical Layer ConvergenceProcedure) Protocol Data Unit) to reduce transmission errors producingerror protected data. The demultiplexing module is operably coupled todivide the error protected data into a plurality of error protected datastreams The plurality of direct conversion modules is operably coupledto convert the plurality of error protected data streams into aplurality of radio frequency (RF) signals.

As one of average skill in the art will appreciate, the wirelesscommunication device of FIG. 2 may be implemented using one or moreintegrated circuits. For example, the host device may be implemented onone integrated circuit, the baseband processing module 64 and memory 66may be implemented on a second integrated circuit, and the remainingcomponents of the radio 60, less the antennae 82-86, may be implementedon a third integrated circuit. As an alternate example, the radio 60 maybe implemented on a single integrated circuit. As yet another example,the processing module 50 of the host device and the baseband processingmodule 64 may be a common processing device implemented on a singleintegrated circuit. Further, the memory 52 and memory 66 may beimplemented on a single integrated circuit and/or on the same integratedcircuit as the common processing modules of processing module 50 and thebaseband processing module 64.

FIG. 3 is a diagram illustrating an embodiment of a radio frequency (RF)transmitter 68-72, or RF front-end, of the WLAN transmitter. The RFtransmitter 68-72 includes a digital filter and up-sampling module 75, adigital-to-analog conversion module 77, an analog filter 79, andup-conversion module 81, a power amplifier 83 and a RF filter 85. Thedigital filter and up-sampling module 75 receives one of the outboundsymbol streams 90 and digitally filters it and then up-samples the rateof the symbol streams to a desired rate to produce the filtered symbolstreams 87. The digital-to-analog conversion module 77 converts thefiltered symbols 87 into analog signals 89. The analog signals mayinclude an in-phase component and a quadrature component.

The analog filter 79 filters the analog signals 89 to produce filteredanalog signals 91. The up-conversion module 81, which may include a pairof mixers and a filter, mixes the filtered analog signals 91 with alocal oscillation 93, which is produced by local oscillation module 100,to produce high frequency signals 95. The frequency of the highfrequency signals 95 corresponds to the frequency of the outbound RFsignals 92.

The power amplifier 83 amplifies the high frequency signals 95 toproduce amplified high frequency signals 97. The RF filter 85, which maybe a high frequency band-pass filter, filters the amplified highfrequency signals 97 to produce the desired output RF signals 92.

As one of average skill in the art will appreciate, each of the radiofrequency transmitters 68-72 will include a similar architecture asillustrated in FIG. 3 and further include a shut-down mechanism suchthat when the particular radio frequency transmitter is not required, itis disabled in such a manner that it does not produce interferingsignals and/or noise.

FIG. 4 is a diagram illustrating an embodiment of an RF receiver. Thismay depict any one of the RF receivers 76-80. In this embodiment, eachof the RF receivers 76-80 includes an RF filter 101, a low noiseamplifier (LNA) 103, a programmable gain amplifier (PGA) 105, adown-conversion module 107, an analog filter 109, an analog-to-digitalconversion module 111 and a digital filter and down-sampling module 113.The RF filter 101, which may be a high frequency band-pass filter,receives the inbound RF signals 94 and filters them to produce filteredinbound RF signals. The low noise amplifier 103 amplifies the filteredinbound RF signals 94 based on a gain setting 115 and provides theamplified signals to the programmable gain amplifier 105. Theprogrammable gain amplifier further amplifies the inbound RF signals 94before providing them to the down-conversion module 107.

The down-conversion module 107 includes a pair of mixers, a summationmodule, and a filter to mix the inbound RF signals with a localoscillation (LO) 117 that is provided by the local oscillation module100 to produce analog baseband signals. The analog filter 109 filtersthe analog baseband signals and provides them to the analog-to-digitalconversion module 111 which converts them into a digital signal. Thedigital filter and down-sampling module 113 filters the digital signalsand then adjusts the sampling rate to produce the digital samples(corresponding to the inbound symbol streams 96).

FIG. 5 is a diagram illustrating an embodiment of a method for basebandprocessing of data. This diagram shows a method for converting outbounddata 88 into one or more outbound symbol streams 90 by the basebandprocessing module 64. The process begins at Step 110 where the basebandprocessing module receives the outbound data 88 and a mode selectionsignal 102. The mode selection signal may indicate any one of thevarious modes of operation as indicated in tables 1-12. The process thenproceeds to Step 112 where the baseband processing module scrambles thedata in accordance with a pseudo random sequence to produce scrambleddata. Note that the pseudo random sequence may be generated from afeedback shift register with the generator polynomial of S(x)=x⁷+x⁴+1.

The process then proceeds to Step 114 where the baseband processingmodule selects one of a plurality of encoding modes based on the modeselection signal. The process then proceeds to Step 116 where thebaseband processing module encodes the scrambled data in accordance witha selected encoding mode to produce encoded data. The encoding may bedone utilizing any one or more a variety of coding schemes (e.g.,convolutional coding, Reed-Solomon (RS) coding, turbo coding, turbotrellis coded modulation (TTCM) coding, LDPC (Low Density Parity Check)coding, etc.).

The process then proceeds to Step 118 where the baseband processingmodule determines a number of transmit streams based on the mode selectsignal. For example, the mode select signal will select a particularmode which indicates that 1, 2, 3, 4 or more antennae may be utilizedfor the transmission. Accordingly, the number of transmit streams willcorrespond to the number of antennae indicated by the mode selectsignal. The process then proceeds to Step 120 where the basebandprocessing module converts the encoded data into streams of symbols inaccordance with the number of transmit streams in the mode selectsignal. This step will be described in greater detail with reference toFIG. 6.

FIG. 6 is a diagram illustrating an embodiment of a method that furtherdefines Step 120 of FIG. 5. This diagram shows a method performed by thebaseband processing module to convert the encoded data into streams ofsymbols in accordance with the number of transmit streams and the modeselect signal. Such processing begins at Step 122 where the basebandprocessing module interleaves the encoded data over multiple symbols andsubcarriers of a channel to produce interleaved data. In general, theinterleaving process is designed to spread the encoded data overmultiple symbols and transmit streams. This allows improved detectionand error correction capability at the receiver. In one embodiment, theinterleaving process will follow the IEEE 802.11(a) or (g) standard forbackward compatible modes. For higher performance modes (e.g., IEEE802.11(n), the interleaving will also be done over multiple transmitpaths or streams.

The process then proceeds to Step 124 where the baseband processingmodule demultiplexes the interleaved data into a number of parallelstreams of interleaved data. The number of parallel streams correspondsto the number of transmit streams, which in turn corresponds to thenumber of antennae indicated by the particular mode being utilized. Theprocess then continues to Steps 126 and 128, where for each of theparallel streams of interleaved data, the baseband processing modulemaps the interleaved data into a quadrature amplitude modulated (QAM)symbol to produce frequency domain symbols at Step 126. At Step 128, thebaseband processing module converts the frequency domain symbols intotime domain symbols, which may be done utilizing an inverse fast Fouriertransform. The conversion of the frequency domain symbols into the timedomain symbols may further include adding a cyclic prefix to allowremoval of intersymbol interference at the receiver. Note that thelength of the inverse fast Fourier transform and cyclic prefix aredefined in the mode tables of tables 1-12. In general, a 64-pointinverse fast Fourier transform is employed for 20 MHz channels and128-point inverse fast Fourier transform is employed for 40 MHzchannels.

The process then proceeds to Step 130 where the baseband processingmodule space and time encodes the time domain symbols for each of theparallel streams of interleaved data to produce the streams of symbols.In one embodiment, the space and time encoding may be done by space andtime encoding the time domain symbols of the parallel streams ofinterleaved data into a corresponding number of streams of symbolsutilizing an encoding matrix. Alternatively, the space and time encodingmay be done by space and time encoding the time domain symbols ofM-parallel streams of interleaved data into P-streams of symbolsutilizing the encoding matrix, where P=2M In one embodiment the encodingmatrix may comprise a form of:

$\quad\begin{bmatrix}C_{1} & C_{2} & C_{3} & C_{4} & \ldots & C_{{2M} - 1} & C_{2M} \\{- C_{2}^{*}} & C_{1}^{*} & {- C_{4}^{*}} & C_{3}^{*} & \ldots & {- C_{2M}^{*}} & C_{{2M} - 1}\end{bmatrix}$

The number of rows of the encoding matrix corresponds to M and thenumber of columns of the encoding matrix corresponds to P. Theparticular symbol values of the constants within the encoding matrix maybe real or imaginary numbers.

FIGS. 7-9 are diagrams illustrating various embodiments for encoding thescrambled data.

FIG. 7 is a diagram of one method that may be utilized by the basebandprocessing module to encode the scrambled data at Step 116 of FIG. 5. Inthis method, the encoding of FIG. 7 may include an optional Step 144where the baseband processing module may optionally perform encodingwith an outer Reed-Solomon (RS) code to produce RS encoded data. It isnoted that Step 144 may be conducted in parallel with Step 140 describedbelow.

Also, the process continues at Step 140 where the baseband processingmodule performs a convolutional encoding with a 64 state code andgenerator polynomials of G₀=133₈ and G₁=171₈ on the scrambled data (thatmay or may not have undergone RS encoding) to produce convolutionalencoded data. The process then proceeds to Step 142 where the basebandprocessing module punctures the convolutional encoded data at one of aplurality of rates in accordance with the mode selection signal toproduce the encoded data. Note that the puncture rates may include 1/2,2/3 and/or 3/4, or any rate as specified in tables 1-12. Note that, fora particular, mode, the rate may be selected for backward compatibilitywith IEEE 802.11(a), IEEE 802.11(g), or IEEE 802.11(n) raterequirements.

FIG. 8 is a diagram of another encoding method that may be utilized bythe baseband processing module to encode the scrambled data at Step 116of FIG. 5. In this embodiment, the encoding of FIG. 8 may include anoptional Step 148 where the baseband processing module may optionallyperform encoding with an outer RS code to produce RS encoded data. It isnoted that Step 148 may be conducted in parallel with Step 146 describedbelow.

The method then continues at Step 146 where the baseband processingmodule encodes the scrambled data (that may or may not have undergone RSencoding) in accordance with a complimentary code keying (CCK) code toproduce the encoded data. This may be done in accordance with IEEE802.11(b) specifications, IEEE 802.11(g), and/or IEEE 802.11(n)specifications.

FIG. 9 is a diagram of yet another method for encoding the scrambleddata at Step 116, which may be performed by the baseband processingmodule. In this embodiment, the encoding of FIG. 9 may include anoptional Step 154 where the baseband processing module may optionallyperform encoding with an outer RS code to produce RS encoded data.

Then, in some embodiments, the process continues at Step 150 where thebaseband processing module performs LDPC (Low Density Parity Check)coding on the scrambled data (that may or may not have undergone RSencoding) to produce LDPC coded bits. Alternatively, the Step 150 mayoperate by performing convolutional encoding with a 256 state code andgenerator polynomials of G₀=561₈ and G₁=753₈ on the scrambled data thescrambled data (that may or may not have undergone RS encoding) toproduce convolutional encoded data. The process then proceeds to Step152 where the baseband processing module punctures the convolutionalencoded data at one of the plurality of rates in accordance with a modeselection signal to produce encoded data. Note that the puncture rate isindicated in the tables 1-12 for the corresponding mode.

The encoding of FIG. 9 may further include the optional Step 154 wherethe baseband processing module combines the convolutional encoding withan outer Reed Solomon code to produce the convolutional encoded data.

FIGS. 10A and 10B are diagrams illustrating embodiments of a radiotransmitter 160. This may involve the PMD module of a WLAN transmitter.In FIG. 10A, the baseband processing is shown to include a scrambler172, channel encoder 174, interleaver 176, demultiplexer 170, aplurality of symbol mappers 180-184, a plurality of inverse fast Fouriertransform (IFFT)/cyclic prefix addition modules 186-190 and a space/timeencoder 192. The baseband portion of the transmitter may further includea mode manager module 175 that receives the mode selection signal 173and produces settings 179 for the radio transmitter portion and producesthe rate selection 171 for the baseband portion. In this embodiment, thescrambler 172, the channel encoder 174, and the interleaver 176 comprisean error protection module. The symbol mappers 180-184, the plurality ofIFFT/cyclic prefix modules 186-190, the space time encoder 192 comprisea portion of the digital baseband processing module.

In operations, the scrambler 172 adds (e.g., in a Galois Finite Field(GF2)) a pseudo random sequence to the outbound data bits 88 to make thedata appear random. A pseudo random sequence may be generated from afeedback shift register with the generator polynomial of S(x)=x⁷+x⁴+1 toproduce scrambled data. The channel encoder 174 receives the scrambleddata and generates a new sequence of bits with redundancy. This willenable improved detection at the receiver. The channel encoder 174 mayoperate in one of a plurality of modes. For example, for backwardcompatibility with IEEE 802.11(a) and IEEE 802.11(g), the channelencoder has the form of a rate 1/2 convolutional encoder with 64 statesand a generator polynomials of G₀=133₈ and G₁=171₈. The output of theconvolutional encoder may be punctured to rates of 1/2, 2/3, and 3/4according to the specified rate tables (e.g., tables 1-12). For backwardcompatibility with IEEE 802.11(b) and the CCK modes of IEEE 802.11(g),the channel encoder has the form of a CCK code as defined in IEEE802.11(b). For higher data rates (such as those illustrated in tables 6,8 and 10), the channel encoder may use the same convolution encoding asdescribed above or it may use a more powerful code, including aconvolutional code with more states, any one or more of the varioustypes of error correction codes (ECCs) mentioned above (e.g., RS, LDPC,turbo, TTCM, etc.) a parallel concatenated (turbo) code and/or a lowdensity parity check (LDPC) block code. Further, any one of these codesmay be combined with an outer Reed Solomon code. Based on a balancing ofperformance, backward compatibility and low latency, one or more ofthese codes may be optimal. Note that the concatenated turbo encodingand low density parity check will be described in greater detail withreference to subsequent Figures.

The interleaver 176 receives the encoded data and spreads it overmultiple symbols and transmit streams. This allows improved detectionand error correction capabilities at the receiver. In one embodiment,the interleaver 176 will follow the IEEE 802.11(a) or (g) standard inthe backward compatible modes. For higher performance modes (e.g., suchas those illustrated in tables 6, 8 and 10), the interleaver willinterleave data over multiple transmit streams. The demultiplexer 170converts the serial interleave stream from interleaver 176 intoM-parallel streams for transmission.

Each symbol mapper 180-184 receives a corresponding one of theM-parallel paths of data from the demultiplexer. Each symbol mapper180-182 lock maps bit streams to quadrature amplitude modulated QAMsymbols (e.g., BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, et cetera) accordingto the rate tables (e.g., tables 1-12). For IEEE 802.11(a) backwardcompatibility, double Gray coding may be used.

The map symbols produced by each of the symbol mappers 180-184 areprovided to the IFFT/cyclic prefix addition modules 186-190, whichperforms frequency domain to time domain conversions and adds a prefix,which allows removal of inter-symbol interference at the receiver. Notethat the length of the IFFT and cyclic prefix are defined in the modetables of tables 1-12. In general, a 64-point IFFT will be used for 20MHz channels and 128-point IFFT will be used for 40 MHz channels.

The space/time encoder 192 receives the M-parallel paths of time domainsymbols and converts them into P-output symbols. In one embodiment, thenumber of M-input paths will equal the number of P-output paths. Inanother embodiment, the number of output paths P will equal 2M paths.For each of the paths, the space/time encoder multiples the inputsymbols with an encoding matrix that has the form of

$\begin{bmatrix}C_{1} & C_{2} & C_{3} & C_{4} & \ldots & C_{{2M} - 1} & C_{2M} \\{- C_{2}^{*}} & C_{1}^{*} & {- C_{4}^{*}} & C_{3}^{*} & \ldots & {- C_{2M}^{*}} & C_{{2M} - 1}\end{bmatrix}.$

The rows of the encoding matrix correspond to the number of input pathsand the columns correspond to the number of output paths.

FIG. 10B illustrates the radio portion of the transmitter that includesa plurality of digital filter/up-sampling modules 194-198,digital-to-analog conversion modules 200-204, analog filters 206-216,I/Q modulators 218-222, RF amplifiers 224-228, RF filters 230-234 andantennae 236-240. The P-outputs from the space/time encoder 192 arereceived by respective digital filtering/up-sampling modules 194-198. Inone embodiment, the digital filters/up sampling modules 194-198 are partof the digital baseband processing module and the remaining componentscomprise the plurality of RF front-ends. In such an embodiment, thedigital baseband processing module and the RF front end comprise adirect conversion module.

In operation, the number of radio paths that are active correspond tothe number of P-outputs. For example, if only one P-output path isgenerated, only one of the radio transmitter paths will be active. Asone of average skill in the art will appreciate, the number of outputpaths may range from one to any desired number.

The digital filtering/up-sampling modules 194-198 filter thecorresponding symbols and adjust the sampling rates to correspond withthe desired sampling rates of the digital-to-analog conversion modules200-204. The digital-to-analog conversion modules 200-204 convert thedigital filtered and up-sampled signals into corresponding in-phase andquadrature analog signals. The analog filters 206-214 filter thecorresponding in-phase and/or quadrature components of the analogsignals, and provide the filtered signals to the corresponding I/Qmodulators 218-222. The I/Q modulators 218-222 based on a localoscillation, which is produced by a local oscillator 100, up-convertsthe I/Q signals into radio frequency signals.

The RF amplifiers 224-228 amplify the RF signals which are thensubsequently filtered via RF filters 230-234 before being transmittedvia antennae 236-240.

FIGS. 11A and 11B are diagrams illustrating embodiments of a radioreceiver (as shown by reference numeral 250). These diagrams illustratea schematic block diagram of another embodiment of a receiver. FIG. 11Aillustrates the analog portion of the receiver which includes aplurality of receiver paths. Each receiver path includes an antenna, RFfilters 252-256, low noise amplifiers 258-262, I/Q demodulators 264-268,analog filters 270-280, analog-to-digital converters 282-286 and digitalfilters and down-sampling modules 288-290.

In operation, the antennae receive inbound RF signals, which areband-pass filtered via the RF filters 252-256. The corresponding lownoise amplifiers 258-262 amplify the filtered signals and provide themto the corresponding I/Q demodulators 264-268. The I/Q demodulators264-268, based on a local oscillation, which is produced by localoscillator 100, down-converts the RF signals into baseband in-phase andquadrature analog signals.

The corresponding analog filters 270-280 filter the in-phase andquadrature analog components, respectively. The analog-to-digitalconverters 282-286 convert the in-phase and quadrature analog signalsinto a digital signal. The digital filtering and down-sampling modules288-290 filter the digital signals and adjust the sampling rate tocorrespond to the rate of the baseband processing, which will bedescribed in FIG. 11B.

FIG. 11B illustrates the baseband processing of a receiver. The basebandprocessing includes a space/time decoder 294, a plurality of fastFourier transform (FFT)/cyclic prefix removal modules 296-300, aplurality of symbol demapping modules 302-306, a multiplexer 308, adeinterleaver 310, a channel decoder 312, and a descramble module 314.The baseband processing module may further include a mode managingmodule 175, which produces rate selections 171 and settings 179 based onmode selections 173. The space/time decoding module 294, which performsthe inverse function of space/time encoder 192, receives P-inputs fromthe receiver paths and produce M-output paths. The M-output paths areprocessed via the FFT/cyclic prefix removal modules 296-300 whichperform the inverse function of the IFFT/cyclic prefix addition modules186-190 to produce frequency domain symbols.

The symbol demapping modules 302-306 convert the frequency domainsymbols into data utilizing an inverse process of the symbol mappers180-184. The multiplexer 308 combines the demapped symbol streams into asingle path.

The deinterleaver 310 deinterleaves the single path utilizing an inversefunction of the function performed by interleaver 176. The deinterleaveddata is then provided to the channel decoder 312 which performs theinverse function of channel encoder 174. The descrambler 314 receivesthe decoded data and performs the inverse function of scrambler 172 toproduce the inbound data 98.

FIG. 12 is a diagram illustrating an embodiment of an access point (AP)and multiple wireless local area network (WLAN) devices operatingaccording to one or more various aspects and/or embodiments of theinvention. The AP point 1200 may compatible with any number ofcommunication protocols and/or standards, e.g., IEEE 802.11(a), IEEE802.11(b), IEEE 802.11(g), IEEE 802.11(n), as well as in accordance withvarious aspects of invention. According to certain aspects of thepresent invention, the AP supports backwards compatibility with priorversions of the IEEE 802.11x standards as well. According to otheraspects of the present invention, the AP 1200 supports communicationswith the WLAN devices 1202, 1204, and 1206 with channel bandwidths, MIMOdimensions, and at data throughput rates unsupported by the prior IEEE802.11x operating standards. For example, the access point 1200 and WLANdevices 1202, 1204, and 1206 may support channel bandwidths from thoseof prior version devices and from 40 MHz to 1.28 GHz and above. Theaccess point 1200 and WLAN devices 1202, 1204, and 1206 support MIMOdimensions to 4×4 and greater. With these characteristics, the accesspoint 1200 and WLAN devices 1202, 1204, and 1206 may support datathroughput rates to 1 GHz and above.

The AP 1200 supports simultaneous communications with more than one ofthe WLAN devices 1202, 1204, and 1206. Simultaneous communications maybe serviced via OFDM tone allocations (e.g., certain number of OFDMtones in a given cluster), MIMO dimension multiplexing, or via othertechniques. With some simultaneous communications, the AP 1200 mayallocate one or more of the multiple antennae thereof respectively tosupport communication with each WLAN device 1202, 1204, and 1206, forexample.

Further, the AP 1200 and WLAN devices 1202, 1204, and 1206 are backwardscompatible with the IEEE 802.11 (a), (b), (g), and (n) operatingstandards. In supporting such backwards compatibility, these devicessupport signal formats and structures that are consistent with theseprior operating standards.

Generally, communications as described herein may be targeted forreception by a single receiver or for multiple individual receivers(e.g. via multi-user multiple input multiple output (MU-MIMO), and/orOFDMA transmissions, which are different than single transmissions witha multi-receiver address). For example, a single OFDMA transmission usesdifferent tones or sets of tones (e.g., clusters or channels) to senddistinct sets of information, each set of set of information transmittedto one or more receivers simultaneously in the time domain. Again, anOFDMA transmission sent to one user is equivalent to an OFDMtransmission. A single MU-MIMO transmission may includespatially-diverse signals over a common set of tones, each containingdistinct information and each transmitted to one or more distinctreceivers. Some single transmissions may be a combination of OFDMA andMU-MIMO. MIMO transceivers illustrated may include SISO, SIMO, and MISOtransceivers. The clusters employed for such communications may becontinuous (e.g., adjacent to one another) or discontinuous (e.g.,separated by a guard interval of band gap). Transmissions on differentOFDMA clusters may be simultaneous or non-simultaneous. Such wirelesscommunication devices as described herein may be capable of supportingcommunications via a single cluster or any combination thereof. Legacyusers and new version users (e.g., TGac MU-MIMO, OFDMA, MU-MIMO/OFDMA,etc.) may share bandwidth at a given time or they can be scheduled atdifferent times for certain embodiments.

FIG. 13 is a diagram illustrating an embodiment of a wirelesscommunication device, and clusters, as may be employed for supportingcommunications with at least one additional wireless communicationdevice. Generally speaking, a cluster may be viewed as a depiction ofthe mapping of tones, such as for an OFDM symbol, within or among one ormore channels (e.g., sub-divided portions of the spectrum) that may besituated in one or more bands (e.g., portions of the spectrum separatedby relatively larger amounts). As an example, various channels of 20 MHzmay be situated within or centered around a 5 GHz band. The channelswithin any such band may be continuous (e.g., adjacent to one another)or discontinuous (e.g., separated by some guard interval or band gap).Oftentimes, one or more channels may be situated within a given band,and different bands need not necessarily have a same number of channelstherein. Again, a cluster may generally be understood as any combinationone or more channels among one or more bands.

The wireless communication device of this diagram may be of any of thevarious types and/or equivalents described herein (e.g., AP, WLANdevice, or other wireless communication device including, though notlimited to, any of those depicted in FIG. 1, etc.). The wirelesscommunication device includes multiple antennae from which one or moresignals may be transmitted to one or more receiving wirelesscommunication devices and/or received from one or more other wirelesscommunication devices.

Such clusters may be used for transmissions of signals via various oneor more selected antennae. For example, different clusters are shown asbeing used to transmit signals respectively using different one or moreantennae.

One operation that may be performed within certain communication systemsinvolves performing channel estimation of the various wirelesscommunication channels between at least a first wireless communicationdevice and a second wireless communication device. In accordance withsuch channel estimation, a channel sounding may be transmitted from atransmitting wireless communication device to a receiving wirelesscommunication device; in response to the channel sounding, the receivingwireless communication device may then provide feedback to thetransmitting wireless communication device to assist in subsequentbeamforming as applied to subsequent communications sent from thetransmitting wireless communication device to one or more the receivingwireless communication devices.

Of course, it is noted that the general nomenclature employed hereinwherein a transmitting wireless communication device (e.g., such asbeing an AP, or a STA operating as an ‘AP’ with respect to other STAs)initiates communications, and/or operates as a network controller typeof wireless communication device, with respect to a number of other,receiving wireless communication devices (e.g., such as being STAs), andthe receiving wireless communication devices (e.g., such as being STAs)responding to and cooperating with the transmitting wirelesscommunication device in supporting such communications. Of course, whilethis general nomenclature of transmitting wireless communicationdevice(s) and receiving wireless communication device(s) may be employedto differentiate the operations as performed by such different wirelesscommunication devices within a communication system, all such wirelesscommunication devices within such a communication system may of coursesupport bi-directional communications to and from other wirelesscommunication devices within the communication system. In other words,the various types of transmitting wireless communication device(s) andreceiving wireless communication device(s) may all supportbi-directional communications to and from other wireless communicationdevices within the communication system.

A novel format for such feedback is presented herein for use in explicittransmit beamforming for subsequent communications sent from thetransmitting wireless communication device to one or more receivingwireless communication devices. Such a format as made herein allows forexplicit transmit beamforming in accordance with wireless communicationscompliant with the IEEE Task Group ac (TGac VHTL6).

The format of the feedback employs the compressed V feedback format forsingle user multiple input multiple output (SU-MIMO). That is to say,for SU-MIMO applications, a common feedback frame format may be employedsuch as that which is employed for compressed V feedback. In addition,minor extensions may be added to SU-MIMO feedback format to improve andguarantee channel state information quality for multi-user multipleinput multiple output (MU-MIMO) transmit beamforming (TXBF).

With respect to the requirements on the feedback information, SU-MIMOand MU-MIMO have different requirements on channel feedback for suchTXBF.

With respect to the feedback information as performed and applied inaccordance with SU-MIMO, it is important to grant beamformee theflexibility to choose appropriate steering matrices, including the rankof the V matrix (e.g., the beamforming steering matrix, being anM_(T)×M_(T) dimensional steering matrix, where T is the number oftransmit antennae, and the matrix V may be obtained from the singularvalue decomposition (SVD) of the channel matrix). Such transmitbeamforming (TXBF) may work well even with less than perfect channelstate information in accordance with SU-MIMO applications.

With respect to the feedback information as performed and applied inaccordance with MU-MIMO, MU-MIMO is a promising technology aimed atincreasing the aggregate network throughput, and in some cases, it canprovide for performance that is far above the throughput achievable inaccordance with SU-MIMO applications.

It is of course noted that efficient MU-MIMO operation may require moreaccurate and more complete channel knowledge than is required inaccordance with SU-MIMO.

Incomplete and inaccurate channel feedback from one receiving wirelesscommunication device (e.g., a wireless station (STA)) may not only hurtits own respective performance, but such incomplete information may alsojeopardize the overall network throughput due to interferences that maybe caused within a multi-user (MU) communication system.

A unified feedback format and framework, as constructed in accordancewith the novel principles presented herein, may be applied for bothSU-MIMO and MU-MIMO communication systems. In other words, a unifiedfeedback format (e.g., accommodating different feedback requirementswith one common feedback framework) may be applied to both SU-MIMO andMU-MIMO communication systems thereby avoiding any need for respectiveand different feedback formats for the two communication system types.As such, a beamformee (e.g., receiving wireless communication device)does not need to implement two separate and different approaches toprepare the feedback information before providing it to the transmittingwireless communication device.

To meet requirements for MU-MIMO, minor extensions may be introduced toSU-MIMO feedback format while operating in accordance with the samefeedback framework. The minor extensions may be targeted to focus onextensions that can bring a greatest degree of benefits for MU-MIMOTXBF, and also those that require no additional computations (e.g.,thereby conserving hardware resources and budgets).

FIG. 14, FIG. 15, FIG. 16, and FIG. 17 are diagrams illustrating variousembodiments of simulation results showing the effects of feedback rankand accuracy. With respect to these simulation results, it can be seenthat higher feedback granularity may generally be required to maintainminimal loss at high signal to noise ratio (SNR). Feedback correspondingto those V matrices having the highest rank may not be necessary in allcases. For example, as the size of the V matrices increased as afunction of an increase in the number of antennae in such MIMOapplications, an acceptable degree of performance may be achieved usingthose V matrices that have less than the highest rank. For example, insome communication channels exhibiting lower angular spread, feedbackassociated with a lower rank (e.g., rank-1 feedback) may provideadequate and acceptable performance. It is also noted that, in certainembodiments, it may be preferable to allow the transmitting wirelesscommunication device (e.g., an Access point (AP)) to request the rankcorresponding to the feedback V matrix and the desired accuracy in orderto provides for a better or best trade off that the feedback overheadwith downlink (DL) performance.

A novel approach for the format to be employed in accordance withexplicit feedback format, as applicable to both SU-MIMO and MU-MIMOcommunication system applications.

In accordance with one embodiment, one bit may be added in a non-datapacket announcement (NDP-A) frame (e.g., such as that which may precedeand indicate a subsequent channel sounding) to indicate feedback inaccordance with either SU-feedback or MU-feedback (e.g., such asdescribed in reference [4]). For example, this one bit being set to avalue of 0 may indicate SU-MIMO feedback operation, and the one beingset to a value of 1 may indicate MU-MIMO feedback operation, or viceversa.

For SU-MIMO applications, the explicit feedback format may operate inaccordance with the same compressed V feedback format described inSections 20.3.12.2.5 and 7.3.1.29 of IEEE 802.11n—2009 with certainstraightforward extensions (e.g., as described below with respect to theAPPENDIX) for wireless communication devices employing from 5 up to 8transmit/receive (TX/RX) antennae.

For MU-MIMO applications, the explicit feedback format may be slightlyadapted to add certain of the following extension to the compressed Vfeedback format described in accordance with IEEE 802.11n.

One of the possible extensions involves adding per-tone eigen-values(e.g., corresponding to the V matrices). This could also be extended toper-sub-band eigen-values (e.g. each 20 MHz sub-band share a set ofcommon eigen-values) to save or reduced feedback overhead. That is tosay, a compressed beamforming feedback frame may be employed thatincludes a number of per-tone or per-sub-band eigen-values correspondingto the respective V matrices, associated with a feedback frame, that areemployed by a beamformer to calculate the appropriate steering matricesfor subsequent transmissions from the beamformer (e.g., a transmitter)to a beamformee (e.g., a receiver).

Another of the possible extensions involves increasing quantizationresolutions of the feedback information. This may operate to increasethe codebook information field in the MIMO control field (e.g.,modify/increase such a field such as with respect to FIGS. 7-36 j withinthe IEEE Std 802.11n™—2009, which is incorporated by reference above) upto 3 bits to accommodate higher accuracy quantization. For example, byemploying up to three bits, as many as eight different values could berepresented. For instance, a channel bandwidth may be indicated within aMIMO control channel width field adaptive for indicating more than twodifferent channel widths. For example, as described with respect otherembodiments herein, various channel widths may be employed forcommunications including those being 20 MHz, 40 MHz, 80 MHz, and 160MHz. By employing more bits, an increased number of channel widths maybe represented. For example, if only one bit is employed, then only topossible channel widths may be represented (e.g., having the bit set toone value for one channel width and having the bit set to another valuefor another channel width). By employing additional bits, at least three(e.g., more than two) separate and distinct channel widths may berepresented. In one embodiment, if two bits are employed, then up tofour different channel widths may be represented. In another embodiment,if three bits are employed, then up to eight different channel widthsmay be represented. Generally speaking, if additional bits are employed,then greater number of separate and distinct channel widths may berepresented within a MIMO control channel width field.

Yet another of the possible extensions involves having the beamformer(e.g., transmitting wireless communication device such as an AP) requesta certain feedback rank of the V matrix. The request can be indicated inan NDP-A frame transmitted from a transmitting wireless communicationdevice. A receiving wireless communication device that receives an NDP-Aframe may process that received frame to determine a requested feedbackrank of a steering matrix that the transmitting wireless communicationdevice would prefer. In such an instance, the receiving wirelesscommunication device may be viewed as being a beamformee and thetransmitting wireless communication device may be viewed as being abeamformer. In accordance with generating a compressed beamformingfeedback frame, such a receiving wireless communicationdevice/beamformee may generate such a compressed beamforming feedbackframe in accordance with the requested feedback rank as indicated andrequested by the transmitting wireless communication device/beamformer.

A compressed beamforming approach is being employed herein in accordancewith the development of technology for channel feedback in ACcord (e.g.,IEEE 802.11ac). Herein, various further details are presented for use inaccordance with such development.

Angle Resolution

FIG. 18 is a diagram illustrating an embodiment of an angle resolutiontable. It has been observed in multi-user (MU) simulations that averageangle (φ and ψ) quantization of 8 bits is required to achievepractically no loss of throughput. It has also been observed in SUsimulations employing wireless communication devices with 8 antennasthat an increase of resolution to (5,7) may be useful. Herein, anincrease to the codebook information table is made thereby extending to3 bits and adding the following resolutions (bψ, bφ)={(5,7), (6,8),(7,9), reserved. As such, the angle resolution table is as show in thediagram. In a preferred embodiment, certain of the resolutions may beemployed for SU-MIMO, and other of the resolutions they be employed forMU-MIMO. Depending upon an operational mode being employed within agiven wireless communication system and/or by a given wirelesscommunication device (e.g., such as operating in accordance with SU-MIMOor MU-MIMO), different respective angle resolution values may beincluded within a given compressed beamforming feedback frame. As can beseen in the lower part of the diagram, certain selected angle resolutionvalues correspond to SU-MIMO, and other selected angle resolution valuescorrespond to MU-MIMO.

Tone Grouping

Uniform sampling of the frequency domain is typically employed andallows simple and efficient interpolation schemes. As such, certainembodiments presented herein that are directed towards and applicablefor applications related to IEEE 802.11ac operate using a baselineuniform tone grouping with options 1, 2 and 4 as recommended inreference [6]. However, typical interpolation schemes may sufferperformance loss at the band edge. One approach by which performance maybe improved is to increase the tone density at the band edge. While someembodiments presented and described herein operate in accordance withseeking to improve tone density advantages, employing non-uniformsampling of the frequency domain, etc., it is nonetheless noted thatmany embodiments operate using uniform sampling of the frequency domain.

The performance improvement will depend on the channel delay spread,specific interpolation scheme, signal bandwidth (e.g., 20 MHz, 40 MHz,80 MHz, etc.), and the accuracy of the feedback information.

Extensive simulation results for various MIMO configurations have beenperformed with respect to variants of channel bandwidth, number of addedtones at the band edge, etc. Herein, certain embodiments propose to adda certain flexibility to allow a transmitting wireless communicationdevice (e.g., an access point (AP)) to request increased tone densityfrom the various receiving wireless communication devices (e.g., STAs).

In addition, the baseline tone mapping may be augmented with thefollowing signaling in the MIMO control field. Three (3) zones may bedefined based on the requested tones in the baseline mapping as follows:

Zone 1—from the outermost tone (on both edges of the BW) to the secondoutermost

Zone 2—from second outermost tone to the third outermost

Zone 3—from the first tone near DC to the second (on both sides of DC)

If the baseline tone grouping requested is 4, then the transmittingwireless communication device (e.g., AP) can request tone grouping 1 or2 in each of the zones. If the baseline is 2, then the transmittingwireless communication device (e.g., AP) can request tone grouping of 1.

In addition, the following bits may be added:

-   -   1 bit to signal whether the AP requests added tones—can also use        the reserved value in the current grouping field    -   3 bits to signal the requested increased density in each of the        3 defined zones. Each bit means:        -   If baseline tone grouping is 4—1 means tone grouping 2, 0            means tone grouping 1        -   If baseline tone grouping is 2—1 means tone grouping 1

FIG. 19 is a diagram illustrating an embodiment of a tables respectivelyshowing resulting fed back tones with different baseline tone grouping,and particularly, showing tone grouping 2 (with added tone grouping of 1in zones 1 and 2) and tone grouping 4 (with added tone grouping of 1 inzone 1). The tables in this diagram show the resulting fed back toneswith different baseline tone grouping and respectively with:

-   -   Tone grouping 2—added tone grouping of 1 in zones 1 and 2    -   Tone grouping 4—added tone grouping of 1 in zone 1

Per-Tone-SNR for MU-Type Feedback

It has been observed in simulations that providing per-tone-SNR isespecially useful with tone grouping of 4 and with partial rankfeedback. As such, various embodiments presented herein includeproviding per-tone-SNR related feedback. In addition, it is proposed toadd a new field to define the feedback of per-tone-SNR for each spacetime stream.

Also, it is proposed to define the per-tone-SNR for each space timestream as the deviation in dB relative to the fed back average SNR perspace-time stream (1 to Nc).

The new sub-field has additional 4×Nc bits per tone:

-   -   Feedback granularity is 1 dB. Feedback range −8 to 7 dB with 4        bits for each space-time stream    -   This new sub-field is added in Compressed Beamforming Report        field.

Whether the report field includes per-tone-SNR depends on the SU/MU-typefeedback request by the beamformer (e.g., the transmitting wirelesscommunication device (e.g., AP)).

Interpolation

With tone grouping >1, the beamformer (e.g., transmitting wirelesscommunication device (e.g., AP)) may perform interpolation acrossfrequency. However, since the channel feedback is based on feedback ofthe eigen-values and eigenvectors {S,V}, normal interpolation methodsthat assume smoothness of the channel will typically fail to provideadequate results due to discontinuity of the singular vectors V from onetone to another.

Therefore, artificial smoothing may be used to reconstruct anartificially smooth channel before interpolation takes place. Forexample, very good performance is achieved by creating Hi=UiSiVi′ wherethe pair {Si,Vi} is the fed back information for tone (subcarrier) i andUi is found as follows:

-   -   [uu,ss,vv]=SVD(HkViSi)    -   Ui=uu*vv′

The operator ( )′ is the conjugate transpose of a matrix and SVD is thesingular value decomposition. The subscripts k and i denote two adjacentsubcarriers from the list of fed back tones. Hk was the channel found inthe previous iteration.

The approach starts from a tone at one end of the bandwidth and createsH1=S1V1′ and then progresses across the fed back tones one by one tocreate a channel which is smooth relative to the previous one:Hi=UiSiVi′ where Ui was found using the previously generated Hk and thepair {Si,Vi}.

After an artificially smooth channel Hi has been created, several knowninterpolation schemes can be used such as linear interpolation or FFTsmoothing. For example, FFT smoothing is a very good interpolationalgorithm and is described as follows:

The frequency domain channel is multiplied by a window such as a Hammingwindow to reduce band edge effects. The result is converted to timedomain via IFFT. The first N samples in the time domain are kept andconverted back into frequency using FFT.

-   -   N can be determined based on the channel delay spread

The resulting frequency domain samples are multiplied by the inverse ofthe window to restore the original amplitudes. Some of the tones at theedge are replaced by the added tones that were fed back as describedabove (e.g., with respect to augmenting the baseline tone mapping withvarious signaling in the MIMO control field).

FIG. 20 is a diagram illustrating an embodiment of a very highthroughput (VHT) long multiple input multiple output (MIMO) controlfield and feedback field formats for multi-user (MU) and single-user(SU), respectively. In accordance with the various novel solutionspresented herein that may be employed in accordance with variousimplementations of the IEEE 802.11ac standard (e.g., ACcord), thefeedback frame for both single-user (SU) and multi-user (MU) asAction-No-Ack frame based on section 7.4.10.8. Herein, the following VHTMIMO Ctrl Field and feedback report field formats are proposed formulti-user (MU) and single-user (SU).

FIG. 21 is a diagram illustrating an embodiment of a codebookinformation table with 2 bits in the feedback report.

Angle Resolution

It has been observed in MU simulations that average angle (φ and ψ)quantization of 6 (or more number of) bits for 4 Tx and 7˜8 bits for 8Tx is required to achieve practically no loss of through this put, asdescribed in references [7,11,12]. It is shown for SU-MIMO that averageangle quantization of 3˜4 bits is typically used with 2 to 4 transmit(Tx) antennae [7]. An additional bit may be appropriately added forwireless communication devices using 8 transmit (Tx) antennae. As such,the codebook information table depicted in the diagram with 2 bits inthe feedback report is suggested.

FIG. 22 is a diagram illustrating an embodiment of a simulation for SUwith 8 transmit antennae. This simulation is for a 4×4 configuration inan IEEE 802.11n communication system (as the worst case), packet errorrate (PER) simulation show that (3,5) bit resolution is good enough toachieve within a few fractional dB from PER with floating point feedback(full resolution) as described in reference [7]. For an embodimentincluding an 8 transmit (Tx) antennae configuration, one more bit perangle may be employed in order to ensure no loss of performance loss dueto quantization error.

FIG. 23 is a diagram illustrating an embodiment of a VHT MIMO controlfield. The fields that are common for both SU and MU operational modesare as shown in the diagram and as follows:

MU→0: SU feedback (FB)

-   -   1: MU FB

Nc: 0˜7 correspond to 1˜8 columns

Nr: 0˜7 correspond to 1˜8 rows

BW→0: 20 MHz

-   -   1: 40 MHz    -   2:80 MHz    -   3: 160 MHz

Ng→0: Ng=1 1: Ng=2 2:Ng=4

Codebook Information:

When operating in SU Mode (e.g., when MU-type bit is not set)

-   -   0: Reserved    -   1: (2,4)    -   2: (3,5)    -   3: (4,6)

When operating in MU Mode (e.g., when MU-type bit is set)

-   -   0: Reserved    -   1: (5,7)    -   2: (6,8)    -   3: (7,9)

Sounding Sequence Number

Fields that are valid only for the MU Mode may be defined as desired andappropriate for a given embodiment.

Tone Grouping

FIG. 24 is a diagram illustrating an embodiment of tone mapping withgrouping. Uniform sampling of the frequency domain may be employedthereby allowing simple and efficient interpolation schemes. It isproposed that the IEEE 802.11ac then utilizes a baseline uniform tonegrouping with options 1, 2 and 4 as recommended in [9].

However, interpolation schemes may suffer performance loss at the bandedge. As such, tone density may be compensated at the band edge tocounter such deleterious effects. The performance improvement willdepend on the channel delay spread, specific interpolation scheme,signal bandwidth and accuracy of the feedback, etc.

Extensive simulation results have been performed for various MIMOconfigurations including variations of channel bandwidth and number ofadded tones at the band edge; it is also proposed to add a certainflexibility to allow the transmitting wireless communication device(e.g., AP) to request the increased tone density.

Tone Mapping with Grouping

The tables depicted in the diagram show the resulting fed back toneswith different baseline tone grouping and with possible toneaugmentation at the band edge and around DC:

-   -   80+80 MHz has the same pattern with 80 MHz tone mapping below        for each band.    -   For contiguous 160 MHz, tone mapping for 80 MHz is shifted by        ±128 tones.    -   Basically, when tone augmentation is not used, tone mapping with        grouping of 2 and 4 starts at tone edge and ends at the lowest        tone near DC for both negative/positive tone range, excluding        null tones.

In accordance with the existent operation of ACcord (e.g., IEEE802.11ac) as described with respect to reference [8], a receivingwireless communication device (e.g., STA or wireless station) that iscapable of receiving MU-MIMO communications shall be required to includeadditional fields as may be included as appropriate to a givenapplication or context. For example, a minimum rank for the feedback ofV, per tone SNR, or singular values, etc., are such fields that may beadded upon indication that MU-type feedback is requested.

Certain fields that may be added should be compliant to support MU-typefeedback. This consideration is particularly appropriate with respect toproviding per-tone-SNR information. Of course, additional fields may beadded for MU-type feedback as well.

Per-Tone-SNR for MU-Type Feedback

Unlike SU-MIMO, where feedback of the pair {V,MCS} is sufficient, knownMU-MIMO precoding methodologies benefit from knowledge of the transmitcorrelation H^(H)H. It is proposed herein to add a new field(MU-exclusive Beamforming Report field) at the end of CompressedBeamforming Report field, in order to define the feedback ofper-tone-SNR for each space time stream when MU-type feedback isindicated.

This may be defined the per-tone-SNR for each space time stream as thedeviation in dB relative to the fed back average SNR per space-timestream (1 to Nc). The new field has an additional 4×Nc bits per tone inaccordance with the specifications as follows:

-   -   Feedback granularity is 1 dB. Feedback range −8 to 7 dB with 4        bits for each space-time stream.    -   This new field (per-tone-SNR) is added in MU-exclusive        Beamforming Report field    -   It is signaled by the beamformee (e.g., receiving wireless        communication device or STA) using MU-type bit in MIMO control        field (such as described with respect to FIG. 23). Whether the        report field includes per-tone-SNR depends on the SU/MU-type        feedback which is requested by the beamformer.

FIG. 25 is a diagram illustrating an embodiment of a simulation resultscorresponding to a communication system in which a transmitting wirelesscommunication device has 4 antennae and each of 4 receiving wirelesscommunication devices has a respective 1 antenna.

FIG. 26 is a diagram illustrating an embodiment of per-tone signal tonoise ratio (SNR) field in a MU-exclusive beamforming report. Thisdiagram corresponds to a per-tone-SNR field as may be included within aMU-exclusive beamforming report. The proposed field for per-tone-SNR isshown as in the diagram.

Each field for per-tone-SNR at each tone is in the order of the columnsof corresponding V matrix: Nd bits for the first column of correspondingV are followed by Nd bits for the second column and so on, up to thelast Nc_th column of corresponding V at each tone. The corresponding Vis reported in the Compressed Beamforming field (such as in accordancewith FIG. 20).

Definition of Per-Tone-SNR

-   -   Per-Tone-SNR        -   Delta-SNR    -   Size        -   Nd=4 bits    -   Meaning        -   The deviation in dB relative to the fed back average SNR per            space-time-stream (1 to Nc), from −2̂(Nd/2) dB to 2̂(Nd/2)−1            dB

FIG. 27A, FIG. 27B, and FIG. 27C illustrate various embodiments ofmethods for operating a communication device.

Referring to method 2700 of FIG. 27A, the method 2700 begins byreceiving a frame from a wireless communication device, as shown in ablock 2710. The frame may be an NDP-A such as described with respect toother embodiments therein, or maybe some other type of frame. Generallyspeaking, such a receipt frame may be employed for determiningparticularly the type of feedback information and format thereof to beprovided to the wireless communication device. Such exchanges may beunderstood with respect to a relationship between a beamformer ortransmitting wireless communication device and a beamformee or receivingwireless communication device. Such transmitting and receiving wirelesscommunication devices may be any type of wireless communication devices.In some instances, a transmitting wireless communication device is anaccess point (AP), and a receiving wireless communication device is awireless station (STA), or vice versa. In other instances, both thetransmitting and the receiving wireless communication devices are STAs.

The method 2700 continues by determining whether the frame provide someindication relating to the type of feedback format to be provided (e.g.,such as whether the feedback format should be in accordance with SU-MIMOor MU-MIMO), as shown in a block 2720. In some instances, a value of aparticular bit within a predetermined location within the frame willindicate the type of feedback format to be provided. For example, if agiven bit within a particular location of the frame is set to 1, thenthe feedback format should be in accordance with SU-MIMO, and if thatgiven bit within that particular location of the frame set 1, then thefeedback format should be in accordance with MU-MIMO. As may beunderstood, by analyzing a particular value of this particular bit, areceiving wireless communication device may ascertain the operationalmode in which it is operating, whether that be in accordance with aSU-MIMO operational mode or a MU-MIMO operational mode.

The method 2700 then operates by determining whether or not operation isin accordance with SU-MIMO and an associated feedback format is to beprovided in accordance with SU-MIMO, as shown in a block 2730. Ifoperation is in accordance with SU-MIMO, then the method 2700 continuesby generating a first beamforming feedback frame, as shown in a block2740. Such a beamforming feedback frame is adapted up to eight antennae,or even more antennae. That is to say, certain wireless communicationdevices may operate with more than four transmit/receive antennae. Sucha beamforming feedback frame, as may be constructed in accordance withblock 2740, maybe adaptive generally up to any desired number ofantennae.

Alternatively, if operation is not in accordance with SU-MIMO and isinstead determined to be in accordance with MU-MIMO, then the method2700 continues by generating a second beamforming feedback frame, asshown in a block 2750. Such a beamforming feedback frame may have anynumber of particular properties. For example, such a beamformingfeedback frame may include per-tone or per-sub-band eigen-values,respective channel bandwidth indication, etc., as shown in a block 2750.

The method 2700 then operates by transmitting the first or the secondbeamforming feedback frame to the wireless communication device, asshown in a block 2760. It is noted that different respective beamformingfeedback frames may be transmitted to the wireless communication deviceat different times. For example, during a first time and in accordancewith a SU-MIMO operational mode, the first beamforming feedback framemay be transmitted to the wireless communication device. Then, during asecond time in accordance with a MU-MIMO operational mode, the secondbeamforming feedback frame may be transmitted to the wirelesscommunication device. As can be seen, a given receiving wirelesscommunication device may provide beamforming feedback frames ofdifferent types in accordance with different formats.

Referring to method 2701 of FIG. 27B, the method 2701 begins byreceiving a frame from a wireless communication device, as shown in ablock 2711. The frame may be an NDP-A such as described with respect toother embodiments therein, or maybe some other type of frame. Generallyspeaking, such a receipt frame may be employed for determiningparticularly the type of feedback information and format thereof to beprovided to the wireless communication device.

The method 2701 then operates by determining a feedback rank of asteering matrix as indicated in the frame, as shown in a block 2721. Forexample, the frame is received may include a request therein for aparticular feedback rank of the steering matrix. In such an instance,this requested feedback rank may be determined upon analysis of thereceived frame.

The method 2701 then continues by generating a beamforming feedbackframe in accordance with the determine feedback rank, as shown in ablock 2731. The method 2701 then operates by transmitting thebeamforming feedback frame to the wireless communication device, asshown in a block 2741.

Referring to method 2702 of FIG. 27C, the method 2702 begins bygenerating a beamforming feedback frame indicating at least one of arespective plurality of angle resolution values associated with theparticular operational mode being employed (e.g., SU-MIMO or MU-MIMO)and per-tone SNR information values corresponding to each space-timestream, as shown in a block 2712. If desired, any number of othercharacteristics may be included within the beamforming feedback frame aswell. For example, such a beamforming feedback frame may includeindication of a corresponding channel with being employed, whether thatis 20 MHz, 40 MHz, 80 MHz, or 160 MHz.

The method 2702 then continues by transmitting the beamforming feedbackframe to the wireless communication device, as shown in a block 2722.

It is also noted that the various operations and functions as describedwith respect to various methods herein may be performed within awireless communication device, such as using a baseband processingmodule and/or a processing module implemented therein (e.g., such as inaccordance with the baseband processing module 64 and/or the processingmodule 50 as described with reference to FIG. 2) and/or other componentstherein.

For example, such a baseband processing module and/or a processingmodule (which may be implemented in the same device or separate devices)can perform generation of a beamforming feedback frame, as well asgeneration of a signal including such a beamforming feedback frame andtransmission of that signal using at least one of any number of radiosand at least one of any number of antennae of a wireless communicationdevice in accordance with various aspects of the invention, and/or anyother operations and functions as described herein, etc. or theirrespective equivalents. In some embodiments, such a beamforming feedbackframe is generated cooperatively by a processing module in a firstdevice, and a baseband processing module within a second device. Inother embodiments, such a beamforming feedback frame is generated whollyby a baseband processing module.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

As may also be used herein, the terms “processing module”, “module”,“processing circuit”, and/or “processing unit” (e.g., including variousmodules and/or circuitries such as may be operative, implemented, and/orfor encoding, for decoding, for baseband processing, etc.) may be asingle processing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, and/or processing unit may have anassociated memory and/or an integrated memory element, which may be asingle memory device, a plurality of memory devices, and/or embeddedcircuitry of the processing module, module, processing circuit, and/orprocessing unit. Such a memory device may be a read-only memory (ROM),random access memory (RAM), volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module,module, processing circuit, and/or processing unit includes more thanone processing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

The present invention has been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention. Further, theboundaries of these functional building blocks have been arbitrarilydefined for convenience of description. Alternate boundaries could bedefined as long as the certain significant functions are appropriatelyperformed. Similarly, flow diagram blocks may also have been arbitrarilydefined herein to illustrate certain significant functionality. To theextent used, the flow diagram block boundaries and sequence could havebeen defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claimed invention. One of average skill in the artwill also recognize that the functional building blocks, and otherillustrative blocks, modules and components herein, can be implementedas illustrated or by discrete components, application specificintegrated circuits, processors executing appropriate software and thelike or any combination thereof.

The present invention may have also been described, at least in part, interms of one or more embodiments. An embodiment of the present inventionis used herein to illustrate the present invention, an aspect thereof, afeature thereof, a concept thereof, and/or an example thereof. Aphysical embodiment of an apparatus, an article of manufacture, amachine, and/or of a process that embodies the present invention mayinclude one or more of the aspects, features, concepts, examples, etc.described with reference to one or more of the embodiments discussedherein. Further, from figure to figure, the embodiments may incorporatethe same or similarly named functions, steps, modules, etc. that may usethe same or different reference numbers and, as such, the functions,steps, modules, etc. may be the same or similar functions, steps,modules, etc. or different ones.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of the various embodimentsof the present invention. A module includes a functional block that isimplemented via hardware to perform one or module functions such as theprocessing of one or more input signals to produce one or more outputsignals. The hardware that implements the module may itself operate inconjunction software, and/or firmware. As used herein, a module maycontain one or more sub-modules that themselves are modules.

While particular combinations of various functions and features of thepresent invention have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent invention is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

REFERENCES

-   [1] 20100630 Broadcom Feedback Format.ppt-   [2] 20100622 Qualcomm CSI Feedback MU-MIMO.ppt-   [3] 20100706 Marvell Feedback Format.ppt-   [4] 20100707 Broadcom Sounding Format.ppt-   [5] 20100903r3 Accord F2F Tech minutes.doc-   [6] 20100929r0 Atheros FB tone mapping.ppt-   [7] 20100630 Broadcom Feedback Format.ppt-   [8] 20100903r3 Accord F2F Tech minutes.doc-   [9] 20100929r0 Atheros FB tone mapping.ppt-   [10] 20100622r0 Qualcomm CSI Feedback MU-MIMO.ppt-   [11] 20100804r0 Broadcom TxBF Format.ppt-   [12] 20100908r1 Marvell CVFB_SU.ppt

APPENDIX

Size of V Number of The order of angles in the Quantized Beamforming (Nr× Nc) angles (Na) Feedback Matrices Information field 5 × 1  8 φ11, φ21,φ31, φ41, ψ21, ψ31, ψ41, ψ51 5 × 2 14 φ11, φ21, φ31, φ41, ψ21, ψ31, ψ41,ψ51, φ22, φ32, φ42, ψ32, ψ42, ψ52 5 × 3 18 φ11, φ21, φ31, φ41, ψ21, ψ31,ψ41, ψ51, φ22, φ32, φ42, ψ32, ψ42, ψ52, φ33, φ43, ψ43, ψ53 5 × 4 20 φ11,φ21, φ31, φ41, ψ21, ψ31, ψ41, ψ51, φ22, φ32, φ42, ψ32, ψ42, ψ52, φ33,φ43, ψ43, ψ53, φ44, ψ54 5 × 5 20 φ11, φ21, φ31, φ41, ψ21, ψ31, ψ41, ψ51,φ22, φ32, φ42, ψ32, ψ42, ψ52, φ33, φ43, ψ43, ψ53, φ44, ψ54

Size of V Number of The order of angles in the Quantized Beamforming (Nr× Nc) angles (Na) Feedback Matrices Information field 6 × 1 10 φ11, φ21,φ31, φ41, φ51, ψ21, ψ31, ψ41, ψ51, ψ61 6 × 2 18 φ11, φ21, φ31, φ41, φ51,ψ21, ψ31, ψ41, ψ51, ψ61, φ22, φ32, φ42, φ52, ψ32, ψ42, ψ52, ψ62 6 × 3 24φ11, φ21, φ31, φ41, φ51, ψ21, ψ31, ψ41, ψ51, ψ61, φ22, φ32, φ42, φ52,ψ32, ψ42, ψ52, ψ62, φ33, φ43, φ53, ψ43, ψ53, ψ63 6 × 4 28 φ11, φ21, φ31,φ41, φ51, ψ21, ψ31, ψ41, ψ51, ψ61, φ22, φ32, φ42, φ52, ψ32, ψ42, ψ52,ψ62, φ33, φ43, φ53, ψ43, ψ53, ψ63, φ44, φ54, ψ54, ψ64 6 × 5 30 φ11, φ21,φ31, φ41, φ51, ψ21, ψ31, ψ41, ψ51, ψ61, φ22, φ32, φ42, φ52, ψ32, ψ42,ψ52, ψ62, φ33, φ43, φ53, ψ43, ψ53, ψ63, φ44, φ54, ψ54, ψ64, φ55, ψ65 6 ×6 30 φ11, φ21, φ31, φ41, φ51, ψ21, ψ31, ψ41, ψ51, ψ61, φ22, φ32, φ42,φ52, ψ32, ψ42, ψ52, ψ62, φ33, φ43, φ53, ψ43, ψ53, ψ63, φ44, φ54, ψ54,ψ64, φ55, ψ65

Size of V Number of The order of angles in the Quantized Beamforming (Nr× Nc) angles (Na) Feedback Matrices Information field 7 × 1 12 φ11, φ21,φ31, φ41, φ51, φ61, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71 7 × 2 22 φ11, φ21, φ31,φ41, φ51, φ61, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, φ22, φ32, φ42, φ52, φ62,ψ32, ψ42, ψ52, ψ62, ψ72 7 × 3 30 φ11, φ21, φ31, φ41, φ51, φ61, ψ21, ψ31,ψ41, ψ51, ψ61, ψ71, φ22, φ32, φ42, φ52, φ62, ψ32, ψ42, ψ52, ψ62, ψ72,φ33, φ43, φ53, φ63, ψ43, ψ53, ψ63, ψ73 7 × 4 36 φ11, φ21, φ31, φ41, φ51,φ61, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, φ22, φ32, φ42, φ52, φ62, ψ32, ψ42,ψ52, ψ62, ψ72, φ33, φ43, φ53, φ63, ψ43, ψ53, ψ63, ψ73, φ44, φ54, φ64,ψ54, ψ64, ψ74 7 × 5 40 φ11, φ21, φ31, φ41, φ51, φ61, ψ21, ψ31, ψ41, ψ51,ψ61, ψ71, φ22, φ32, φ42, φ52, φ62, ψ32, ψ42, ψ52, ψ62, ψ72, φ33, φ43,φ53, φ63, ψ43, ψ53, ψ63, ψ73, φ44, φ54, φ64, ψ54, ψ64, ψ74, φ55, φ65,ψ65, ψ75 7 × 6 42 φ11, φ21, φ31, φ41, φ51, φ61, ψ21, ψ31, ψ41, ψ51, ψ61,ψ71, φ22, φ32, φ42, φ52, φ62, ψ32, ψ42, ψ52, ψ62, ψ72, φ33, φ43, φ53,φ63, ψ43, ψ53, ψ63, ψ73, φ44, φ54, φ64, ψ54, ψ64, ψ74, φ55, φ65, ψ65,ψ75, φ66, ψ76 7 × 7 42 φ11, φ21, φ31, φ41, φ51, φ61, ψ21, ψ31, ψ41, ψ51,ψ61, ψ71, φ22, φ32, φ42, φ52, φ62, ψ32, ψ42, ψ52, ψ62, ψ72, φ33, φ43,φ53, φ63, ψ43, ψ53, ψ63, ψ73, φ44, φ54, φ64, ψ54, ψ64, ψ74, φ55, φ65,ψ65, ψ75, φ66, ψ76

Size of V Number of The order of angles in the Quantized Beamforming (Nr× Nc) angles (Na) Feedback Matrices Information field 8 × 1 14 φ11, φ21,φ31, φ41, φ51, φ61, φ71, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, ψ81 8 × 2 26 φ11,φ21, φ31, φ41, φ51, φ61, φ71, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, ψ81, φ22,φ32, φ42, φ52, φ62, φ72, ψ32, ψ42, ψ52, ψ62, ψ72, ψ82 8 × 3 36 φ11, φ21,φ31, φ41, φ51, φ61, φ71, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, ψ81, φ22, φ32,φ42, φ52, φ62, φ72, ψ32, ψ42, ψ52, ψ62, ψ72, ψ82, φ33, φ43, φ53, φ63,φ73, ψ43, ψ53, ψ63, ψ73, ψ83 8 × 4 44 φ11, φ21, φ31, φ41, φ51, φ61, φ71,ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, ψ81, φ22, φ32, φ42, φ52, φ62, φ72, ψ32,ψ42, ψ52, ψ62, ψ72, ψ82, φ33, φ43, φ53, φ63, φ73, ψ43, ψ53, ψ63, ψ73,ψ83, φ44, φ54, φ64, φ74, ψ54, ψ64, ψ74, ψ84 8 × 5 50 φ11, φ21, φ31, φ41,φ51, φ61, φ71, ψ21, ψ31, ψ41, ψ51, ψ61, ψ71, ψ81, φ22, φ32, φ42, φ52,φ62, φ72, ψ32, ψ42, ψ52, ψ62, ψ72, ψ82, φ33, φ43, φ53, φ63, φ73, ψ43,ψ53, ψ63, ψ73, ψ83, φ44, φ54, φ64, φ74, ψ54, ψ64, ψ74, ψ84, φ55, φ65,φ75, ψ65, ψ75, ψ85 8 × 6 54 φ11, φ21, φ31, φ41, φ51, φ61, φ71, ψ21, ψ31,ψ41, ψ51, ψ61, ψ71, ψ81, φ22, φ32, φ42, φ52, φ62, φ72, ψ32, ψ42, ψ52,ψ62, ψ72, ψ82, φ33, φ43, φ53, φ63, φ73, ψ43, ψ53, ψ63, ψ73, ψ83, φ44,φ54, φ64, φ74, ψ54, ψ64, ψ74, ψ84, φ55, φ65, φ75, ψ65, ψ75, ψ85, φ66,φ76, ψ76, ψ86 8 × 7 56 φ11, φ21, φ31, φ41, φ51, φ61, φ71, ψ21, ψ31, ψ41,ψ51, ψ61, ψ71, ψ81, φ22, φ32, φ42, φ52, φ62, φ72, ψ32, ψ42, ψ52, ψ62,ψ72, ψ82, φ33, φ43, φ53, φ63, φ73, ψ43, ψ53, ψ63, ψ73, ψ83, φ44, φ54,φ64, φ74, ψ54, ψ64, ψ74, ψ84, φ55, φ65, φ75, ψ65, ψ75, ψ85, φ66, φ76,ψ76, ψ86, φ77, ψ87 8 × 8 56 φ11, φ21, φ31, φ41, φ51, φ61, φ71, ψ21, ψ31,ψ41, ψ51, ψ61, ψ71, ψ81, φ22, φ32, φ42, φ52, φ62, φ72, ψ32, ψ42, ψ52,ψ62, ψ72, ψ82, φ33, φ43, φ53, φ63, φ73, ψ43, ψ53, ψ63, ψ73, ψ83, φ44,φ54, φ64, φ74, ψ54, ψ64, ψ74, ψ84, φ55, φ65, φ75, ψ65, ψ75, ψ85, φ66,φ76, ψ76, ψ86, φ77, ψ87

Mode Selection Tables:

TABLE 1 2.4 GHz, 20/22 MHz channel BW, 54 Mbps max bit rate Code RateModulation Rate NBPSC NCBPS NDBPS ETM Sensitivity ACR AACR Barker 1 BPSKBarker 2 QPSK 5.5 CCK 6 BPSK 0.5 1 48 24 −5 −82 16 32 9 BPSK 0.75 1 4836 −8 −81 15 31 11 CCK 12 QPSK 0.5 2 96 48 −10 −79 13 29 18 QPSK 0.75 296 72 −13 −77 11 27 24 16-QAM 0.5 4 192 96 −16 −74 8 24 36 16-QAM 0.75 4192 144 −19 −70 4 20 48 64-QAM 0.666 6 288 192 −22 −66 0 16 54 64-QAM0.75 6 288 216 −25 −65 −1 15

TABLE 2 Channelization for Table 1 Frequency Channel (MHz) 1 2412 2 24173 2422 4 2427 5 2432 6 2437 7 2442 8 2447 9 2452 10 2457 11 2462 12 2467

TABLE 3 Power Spectral Density (PSD) Mask for Table 1 PSD Mask 1Frequency Offset dBr −9 MHz to 9 MHz 0 +/−11 MHz −20 +/−20 MHz −28 +/−30MHz and −50 greater

TABLE 4 5 GHz, 20 MHz channel BW, 54 Mbps max bit rate Code RateModulation Rate NBPSC NCBPS NDBPS ETM Sensitivity ACR AACR 6 BPSK 0.5 148 24 −5 −82 16 32 9 BPSK 0.75 1 48 36 −8 −81 15 31 12 QPSK 0.5 2 96 48−10 −79 13 29 18 QPSK 0.75 2 96 72 −13 −77 11 27 24 16-QAM 0.5 4 192 96−16 −74 8 24 36 16-QAM 0.75 4 192 144 −19 −70 4 20 48 64-QAM 0.666 6 288192 −22 −66 0 16 54 64-QAM 0.75 6 288 216 −25 −65 −1 15

TABLE 5 Channelization for Table 4 Frequency Frequency Channel (MHz)Country Channel (MHz) Country 240 4920 Japan 244 4940 Japan 248 4960Japan 252 4980 Japan 8 5040 Japan 12 5060 Japan 16 5080 Japan 36 5180USA/Europe 34 5170 Japan 40 5200 USA/Europe 38 5190 Japan 44 5220USA/Europe 42 5210 Japan 48 5240 USA/Europe 46 5230 Japan 52 5260USA/Europe 56 5280 USA/Europe 60 5300 USA/Europe 64 5320 USA/Europe 1005500 USA/Europe 104 5520 USA/Europe 108 5540 USA/Europe 112 5560USA/Europe 116 5580 USA/Europe 120 5600 USA/Europe 124 5620 USA/Europe128 5640 USA/Europe 132 5660 USA/Europe 136 5680 USA/Europe 140 5700USA/Europe 149 5745 USA 153 5765 USA 157 5785 USA 161 5805 USA 165 5825USA

TABLE 6 2.4 GHz, 20 MHz channel BW, 192 Mbps max bit rate TX ST An- CodeMod- Code Rate tennas Rate ulation Rate NBPSC NCBPS NDBPS 12 2 1 BPSK0.5 1 48 24 24 2 1 QPSK 0.5 2 96 48 48 2 1 16-QAM 0.5 4 192 96 96 2 164-QAM 0.666 6 288 192 108 2 1 64-QAM 0.75 6 288 216 18 3 1 BPSK 0.5 148 24 36 3 1 QPSK 0.5 2 96 48 72 3 1 16-QAM 0.5 4 192 96 144 3 1 64-QAM0.666 6 288 192 162 3 1 64-QAM 0.75 6 288 216 24 4 1 BPSK 0.5 1 48 24 484 1 QPSK 0.5 2 96 48 96 4 1 16-QAM 0.5 4 192 96 192 4 1 64-QAM 0.666 6288 192 216 4 1 64-QAM 0.75 6 288 216

TABLE 7 Channelization for Table 6 Channel Frequency (MHz) 1 2412 2 24173 2422 4 2427 5 2432 6 2437 7 2442 8 2447 9 2452 10 2457 11 2462 12 2467

TABLE 8 5 GHz, 20 MHz channel BW, 192 Mbps max bit rate TX ST An- CodeMod- Code Rate tennas Rate ulation Rate NBPSC NCBPS NDBPS 12 2 1 BPSK0.5 1 48 24 24 2 1 QPSK 0.5 2 96 48 48 2 1 16-QAM 0.5 4 192 96 96 2 164-QAM 0.666 6 288 192 108 2 1 64-QAM 0.75 6 288 216 18 3 1 BPSK 0.5 148 24 36 3 1 QPSK 0.5 2 96 48 72 3 1 16-QAM 0.5 4 192 96 144 3 1 64-QAM0.666 6 288 192 162 3 1 64-QAM 0.75 6 288 216 24 4 1 BPSK 0.5 1 48 24 484 1 QPSK 0.5 2 96 48 96 4 1 16-QAM 0.5 4 192 96 192 4 1 64-QAM 0.666 6288 192 216 4 1 64-QAM 0.75 6 288 216

TABLE 9 channelization for Table 8 Frequency Frequency Channel (MHz)Country Channel (MHz) Country 240 4920 Japan 244 4940 Japan 248 4960Japan 252 4980 Japan 8 5040 Japan 12 5060 Japan 16 5080 Japan 36 5180USA/Europe 34 5170 Japan 40 5200 USA/Europe 38 5190 Japan 44 5220USA/Europe 42 5210 Japan 48 5240 USA/Europe 46 5230 Japan 52 5260USA/Europe 56 5280 USA/Europe 60 5300 USA/Europe 64 5320 USA/Europe 1005500 USA/Europe 104 5520 USA/Europe 108 5540 USA/Europe 112 5560USA/Europe 116 5580 USA/Europe 120 5600 USA/Europe 124 5620 USA/Europe128 5640 USA/Europe 132 5660 USA/Europe 136 5680 USA/Europe 140 5700USA/Europe 149 5745 USA 153 5765 USA 157 5785 USA 161 5805 USA 165 5825USA

TABLE 10 5 GHz, with 40 MHz channels and max bit rate of 486 Mbps TX STCode Code Rate Antennas Rate Modulation Rate NBPSC  13.5 Mbps 1 1 BPSK0.5 1   27 Mbps 1 1 QPSK 0.5 2   54 Mbps 1 1 16-QAM 0.5 4   108 Mbps 1 164-QAM 0.666 6 121.5 Mbps 1 1 64-QAM 0.75 6   27 Mbps 2 1 BPSK 0.5 1  54 Mbps 2 1 QPSK 0.5 2   108 Mbps 2 1 16-QAM 0.5 4   216 Mbps 2 164-QAM 0.666 6   243 Mbps 2 1 64-QAM 0.75 6  40.5 Mbps 3 1 BPSK 0.5 1  81 Mbps 3 1 QPSK 0.5 2   162 Mbps 3 1 16-QAM 0.5 4   324 Mbps 3 164-QAM 0.666 6 365.5 Mbps 3 1 64-QAM 0.75 6   54 Mbps 4 1 BPSK 0.5 1  108 Mbps 4 1 QPSK 0.5 2   216 Mbps 4 1 16-QAM 0.5 4   432 Mbps 4 164-QAM 0.666 6   486 Mbps 4 1 64-QAM 0.75 6

TABLE 11 Power Spectral Density (PSD) mask for Table 10 PSD Mask 2Frequency Offset dBr −19 MHz to 19 MHz 0 +/−21 MHz −20 +/−30 MHz −28+/−40 MHz and −50 greater

TABLE 12 Channelization for Table 10 Frequency Frequency Channel (MHz)Country Channel (MHz) County 242 4930 Japan 250 4970 Japan 12 5060 Japan38 5190 USA/Europe 36 5180 Japan 46 5230 USA/Europe 44 5520 Japan 545270 USA/Europe 62 5310 USA/Europe 102 5510 USA/Europe 110 5550USA/Europe 118 5590 USA/Europe 126 5630 USA/Europe 134 5670 USA/Europe151 5755 USA 159 5795 USA

What is claimed is:
 1. A wireless communication device comprising: acommunication interface; and a processing circuitry coupled to thecommunication interface, at least one of the processing circuitry or thecommunication interface configured to: generate a non-data packetannouncement (NDP-A) that includes information that requests single-usermultiple-input-multiple-output (SU-MIMO) feedback or multi-usermultiple-input-multiple-output (MU-MIMO) feedback from another wirelesscommunication device; transmit the NDP-A to the another wirelesscommunication device; when the information within the NDP-A requestsSU-MIMO feedback from the another wireless communication device, receivea first beamforming feedback frame that includes the SU-MIMO feedbackfrom the another wireless communication device; and when the informationwithin the NDP-A requests MU-MIMO feedback from the another wirelesscommunication device, receive a second beamforming feedback frame thatincludes the MU-MIMO feedback from the another wireless communicationdevice.
 2. The wireless communication device of claim 1, wherein the atleast one of the processing circuitry or the communication interface isfurther configured to: set a bit of the information within the NDP-A toa first value to request the SU-MIMO feedback from another wirelesscommunication device; and set the bit of the information within theNDP-A to a second value to request the MU-MIMO feedback from anotherwireless communication device.
 3. The wireless communication device ofclaim 1, wherein the at least one of the processing circuitry or thecommunication interface is further configured to: after receiving thefirst beamforming feedback frame that includes the SU-MIMO feedback fromthe another wireless communication device, generate a beamformed framebased on the first beamforming feedback frame and transmit thebeamformed frame to the another wireless communication device.
 4. Thewireless communication device of claim 1, wherein the at least one ofthe processing circuitry or the communication interface is furtherconfigured to: after receiving the second beamforming feedback framethat includes the MU-MIMO feedback from the another wirelesscommunication device, generate a beamformed frame based on the secondbeamforming feedback frame and transmit the beamformed frame to theanother wireless communication device.
 5. The wireless communicationdevice of claim 1, wherein the at least one of the processing circuitryor the communication interface is further configured to: when theinformation within the NDP-A requests MU-MIMO feedback from the anotherwireless communication device, receive the second beamforming feedbackframe that includes the MU-MIMO feedback from the another wirelesscommunication device and also receive at least one other beamformingfeedback frame that includes at least one other MU-MIMO feedback atleast one other wireless communication device; and after receiving thesecond beamforming feedback frame that includes the MU-MIMO feedbackfrom the another wireless communication device and after receiving theat least one other beamforming feedback frame that includes the at leastone other MU-MIMO feedback the at least one other wireless communicationdevice, generate a beamformed frame based on at least one of the secondbeamforming feedback frame or the at least one other MU-MIMO feedbackand transmit the beamformed frame to at least one of the anotherwireless communication device and the at least one other wirelesscommunication device.
 6. The wireless communication device of claim 1,wherein the at least one of the processing circuitry or thecommunication interface is further configured to: when the informationwithin the NDP-A requests SU-MIMO feedback from the another wirelesscommunication device, receive the first beamforming feedback frame thatincludes the SU-MIMO feedback from the another wireless communicationdevice, wherein the first beamforming feedback frame is in compressedformat that includes a codebook information field that indicates a firstplurality of angle resolution values associated with SU-MIMO operation;and when the information within the NDP-A requests MU-MIMO feedback fromthe another wireless communication device, receive the secondbeamforming feedback frame that includes the MU-MIMO feedback from theanother wireless communication device, wherein second beamformingfeedback frame is in compressed format that includes a codebookinformation field that indicates a second plurality of angle resolutionvalues associated with MU-MIMO operation.
 7. The wireless communicationdevice of claim 1, wherein the at least one of the processing circuitryor the communication interface is further configured to: when theinformation within the NDP-A requests SU-MIMO feedback from the anotherwireless communication device, receive the first beamforming feedbackframe that includes beamforming information for up to eight antennae;and when the information within the NDP-A requests MU-MIMO feedback fromthe another wireless communication device, receive the secondbeamforming feedback frame that includes beamforming information for aplurality of per-tone or per-sub-band eigen-values and a channelbandwidth selected from least three different channel bandwidth values.8. The wireless communication device of claim 1 further comprising: anaccess point (AP), wherein the another wireless communication deviceincludes a wireless station (STA).
 9. A wireless communication devicecomprising: a communication interface; and a processing circuitrycoupled to the communication interface, at least one of the processingcircuitry or the communication interface configured to: generate anon-data packet announcement (NDP-A) that includes a bit set to a firstvalue to request single-user multiple-input-multiple-output (SU-MIMO)feedback or that includes the bit set to a second value to requestmulti-user multiple-input-multiple-output (MU-MIMO) feedback fromanother wireless communication device; transmit the NDP-A to the anotherwireless communication device; when the bit within the NDP-A is set tothe first value, receive a first beamforming feedback frame thatincludes the SU-MIMO feedback from the another wireless communicationdevice and generate a first beamformed frame based on the firstbeamforming feedback frame; and when the bit within the NDP-A is set tothe second value, receive a second beamforming feedback frame thatincludes the MU-MIMO feedback from the another wireless communicationdevice and generate a second beamformed frame based on the secondbeamforming feedback frame.
 10. The wireless communication device ofclaim 9, wherein the processing circuitry is further configured to: whenthe bit within the NDP-A is set to the second value, receive the secondbeamforming feedback frame that includes the MU-MIMO feedback from theanother wireless communication device and also receive at least oneother beamforming feedback frame that includes at least one otherMU-MIMO feedback at least one other wireless communication device; andafter receiving the second beamforming feedback frame that includes theMU-MIMO feedback from the another wireless communication device andafter receiving the at least one other beamforming feedback frame thatincludes the at least one other MU-MIMO feedback the at least one otherwireless communication device, generate a beamformed frame based on atleast one of the second beamforming feedback frame or the at least oneother MU-MIMO feedback and transmit the beamformed frame to at least oneof the another wireless communication device and the at least one otherwireless communication device.
 11. The wireless communication device ofclaim 9, wherein the processing circuitry is further configured to: whenthe bit within the NDP-A is set to the first value, receive the firstbeamforming feedback frame that includes the SU-MIMO feedback from theanother wireless communication device, wherein the first beamformingfeedback frame is in compressed format that includes a codebookinformation field that indicates a first plurality of angle resolutionvalues associated with SU-MIMO operation; and when the bit within theNDP-A is set to the second value, receive the second beamformingfeedback frame that includes the MU-MIMO feedback from the anotherwireless communication device, wherein second beamforming feedback frameis in compressed format that includes a codebook information field thatindicates a second plurality of angle resolution values associated withMU-MIMO operation.
 12. The wireless communication device of claim 9,wherein the at least one of the processing circuitry or thecommunication interface is further configured to: when the bit withinthe NDP-A is set to the first value, receive the first beamformingfeedback frame that includes beamforming information for up to eightantennae; and when the bit within the NDP-A is set to the second value,receive the second beamforming feedback frame that includes beamforminginformation for a plurality of per-tone or per-sub-band eigen-values anda channel bandwidth selected from least three different channelbandwidth values.
 13. The wireless communication device of claim 9further comprising: an access point (AP), wherein the another wirelesscommunication device includes a wireless station (STA).
 14. A method forexecution by a wireless communication device, the method comprising:generating a non-data packet announcement (NDP-A) that includesinformation that requests single-user multiple-input-multiple-output(SU-MIMO) feedback or multi-user multiple-input-multiple-output(MU-MIMO) feedback from another wireless communication device;transmitting, via a communication interface of the wirelesscommunication device, the NDP-A to the another wireless communicationdevice; when the information within the NDP-A requests SU-MIMO feedbackfrom the another wireless communication device, receiving, via thecommunication interface of the wireless communication device, a firstbeamforming feedback frame that includes the SU-MIMO feedback from theanother wireless communication device; and when the information withinthe NDP-A requests MU-MIMO feedback from the another wirelesscommunication device, receiving, via the communication interface of thewireless communication device, a second beamforming feedback frame thatincludes the MU-MIMO feedback from the another wireless communicationdevice.
 15. The method of claim 14 further comprising: setting a bit ofthe information within the NDP-A to a first value to request the SU-MIMOfeedback from another wireless communication device; and setting the bitof the information within the NDP-A to a second value to request theMU-MIMO feedback from another wireless communication device.
 16. Themethod of claim 14 further comprising: after receiving the firstbeamforming feedback frame that includes the SU-MIMO feedback from theanother wireless communication device, generating a beamformed framebased on the first beamforming feedback frame and transmit thebeamformed frame to the another wireless communication device.
 17. Themethod of claim 14 further comprising: after receiving the firstbeamforming feedback frame that includes the SU-MIMO feedback from theanother wireless communication device, generating a beamformed framebased on the first beamforming feedback frame and transmit thebeamformed frame to the another wireless communication device.
 18. Themethod of claim 14 further comprising: when the information within theNDP-A requests SU-MIMO feedback from the another wireless communicationdevice, receiving, via the communication interface of the wirelesscommunication device, the first beamforming feedback frame that includesthe SU-MIMO feedback from the another wireless communication device,wherein the first beamforming feedback frame is in compressed formatthat includes a codebook information field that indicates a firstplurality of angle resolution values associated with SU-MIMO operation;and when the information within the NDP-A requests MU-MIMO feedback fromthe another wireless communication device, receiving, via thecommunication interface of the wireless communication device, the secondbeamforming feedback frame that includes the MU-MIMO feedback from theanother wireless communication device, wherein second beamformingfeedback frame is in compressed format that includes a codebookinformation field that indicates a second plurality of angle resolutionvalues associated with MU-MIMO operation.
 19. The method of claim 14further comprising: when the information within the NDP-A requestsSU-MIMO feedback from the another wireless communication device,receiving, via the communication interface of the wireless communicationdevice, the first beamforming feedback frame that includes beamforminginformation for up to eight antennae; and when the information withinthe NDP-A requests MU-MIMO feedback from the another wirelesscommunication device, receiving, via the communication interface of thewireless communication device, the second beamforming feedback framethat includes beamforming information for a plurality of per-tone orper-sub-band eigen-values and a channel bandwidth selected from leastthree different channel bandwidth values.
 20. The method of claim 14,wherein the wireless communication device includes an access point (AP),and the another wireless communication device includes a wirelessstation (STA).